Vid's comment was:
Gameldar! I'm having exactly the same problem. I have a baby Tauren druid I've been playing around with a little bit - last night I had the bright idea to spec her as a tank and give it a go. I ran RFC 4-5 times (can't quite remember); she's only level 17 yet.
The rage thing is SO FRUSTRATING. And the DPS were not even letting me touch things before they'd be attacking, hunters in particular were giving me a massive headache. Half the time the DPS were tanking...those caster packs towards the end are a nightmare, and even any multi-group was aggravating. You can bet I picked up Glyph of Maul as my first essential glyph. Even then I often didn't have enough rage to start a fight, let alone use Maul or Swipe. Taunt is constantly on CD. Does it not get any better? I'm not sure if I'll be able to stick with it if rage generation continues to be such a debilitating issue; I thought it was just because I am so low-level yet.
Don't lose heart just yet! I ran another 6 dungeons over the weekend and things have improved a bit for me. One of those I was (fail) dps... but the rest I was tanking. I'm now in the graveyard shift so 5/6 of those were in the Scarlet Graveyard and the last one was the Library (I think - the one where you get the key at least). But in general things were improving for the following reasons:
1. I was running dungeons that were red for me in the LFD tool rather than green. So I was effectively out-gearing the content which is always bad for rage. Now I'm taking more damage I'm getting more rage (and making the healers work a bit!)
2. The pulls in the Graveyard (and Library) were generally bigger than anything in Stockades or Gnomergan. This again meant I was taking more damage. It also meant it was easier to lose control of mobs. I, thankfully, also picked up challenging roar when I hit level 28 which I made use of on occasion. Challening Roar and then swipe swipe and everything was generally good! I managed to pull the whole of the first room in the Graveyard - no rage problems then... although I wouldn't recommend that as the healer might have some mana issues (thankfully in the time I did it the healer dinged in the middle and got his mana bar back - in the time I was dpsing I had to drop out of cat form and take over healing as the healer ran out of mana when the tank pulled the whole thing).
3. I bought the Repurposed Lava Dredger (funny looking weapon, and smaller than I thought it would be) - which is the heirloom weapon. This replaced Rhahk'Zor's Hammer which is the drop from the first mini-boss in the Deadmines so it was getting out of date. Now I'll be automatically keeping my weapon up to date. I think it was Darksend noted in his feral druid guide on tankspot.com (I couldn't find the reference again with a quick look - it might have been in the video) one of the best methods of helping rage and threat for a druid is to upgrade your weapon!
4. I've actually had some runs where DPS have waited for me to get aggro. So those types of DPS do still exists... either that or they were just incompetent...
5. And probably most importantly - I've stopped worrying so much about other grabbing aggro. If the warrior wants to charge in an thunderclap everything before I've even got there, I'm happy to let him get hit a bit while I get the rage. I found it generally only took one swipe to pull the mobs back onto me. I've had annoying hunters too - maybe by this level they still haven't learnt to turn of autotargeting? But I had one particular hunter that kept running ahead and pulling mobs... so most the time I just let him tank it (which he ended up doing as he kept pulling aggro of his cat).
I don't know RFC very well as I've mostly played Alliance side (and I haven't run any dungeons with characters in range since LFD was introduced) but if I remember rightly it was a level 13-15 dungeon. This means that if you first entered at level 15 you are already at the top end and basically outgear it. So rage will be a problem there. So I'd at least continue on for deadmines and WFC where you'll be taking more of a beating!
Finally, at level 17 you also don't have Faerie Fire (Feral) yet (comes at 18) - this is an awesome threat tool that should be used on cooldown. As I wrote above, I've found that it pretty much works as another taunt as it is doing enough threat to pull off the dps if you target the mob and hit them with it. It seems strange to have a debuff that is like that - but I've been getting into the habit of using it (I've macroed mine with startattack because I almost always pull with it).
I also pinged Allison Robert of wow.com fame via twitter to see if she had any advice. She replied saying she had had similar experiences recently leveling an alliance side druid recently. Her suggestion was to keep getting the feral talents that increase damage to help with the rage situation. Allison's Bear 101 (as well as her other articles - she is my favourite wow.com writer... I've been reading all that she has written since she wrote some general things about tanks about when 3.0 dropped despite only just starting this druid thing and her clear paladin hate!) is well worth a read too!
So in general I've found it to be getting better as I level, get more experience and get more tools as well. Bears still really do miss a way of getting rage initially - warriors can do it with charge - although they'll need to spec into arms and set up a stance change macro before they get warbringer. But I've also found there is an element of luck involved. I had two graveyard runs one after each other. The first I didn't have rage problems and seemed to be taking more damage, the second I had rage problems - so perhaps I was getting luckier with dodges etc (I was also taking less damage because I had a priest healing me instead of a druid - but the rage is still attributed when absorbed by the priests shields). I'm looking forward to getting the dodge to rage conversion though!
All of this has made me want to try and get into the Cataclysm beta so I can try out low level bear/warrior tanking and be able to give some constructive feedback. I tried to opt in last night and failed - upon which it took me to the Korean battle.net site??? I'll try again but it was late and I couldn't be bothered stuffing around with firewalls etc!
Oh... and I was a bit disappointed about feral charge. It is more of an equivalent to warriors intercept not charge - it costs rage and has a cooldown - it isn't an opener!