However there are a few things that I would like to throw in and they are as follow:
What Guilds will there be??
The guilds from Oblivion will hopefully carry into Skyrim, and with that I also hope to see a few more...
Perhaps the ability to join the guard of a city would be an interesting way to improvise repeatable quests were you settle disputes attack etc...
Joining forest ranger guild, allows you to patrol the frozen wastes as a conservationist, culling beasts and game alike.
Using you status in a guild to attain guild utilities
If you reach a high enough rank, say in the fighters guild you can go out on a contract with a few recruits as a trainer/mentor.
You could also request special weapons, items and armor from the armory.
Mage guild high rankers can order exotic materials and take on an apprentice.
Low ranked thieves are often forced to stand lookout, but later on can command a troop of thieves to do a sweep over an area at a crowded town event with you gaining your 50% cut of course.
Slower Rank gains
I feel that instead of "Hurr complete these 3 quests" the guilds should provide frequent random event missions that help you level a faction bar.
Instead of a quest based rank gain, their should be an influence bar that allows you to slowly gain ranks via quests and different events.
I want it take a fair bit of effort to reach a higher level in a guild, so realistically your level is equivalent to the high ranking NPC levels. (I feel that high ranking members in a guild will have levels implemented, so realistically a high level mage will be much more versatile then a newbie one.)
Thoughts/Questions/Input