The main role for a bureaucrat is social: deciding who gets to be an admin (after whatever process, if any).
In the model I propose, where basically everyone becomes an admin unless there's good reason not to, a bureaucrat's job would be to judge that and swoop on people and bless/curse them with the mop. So admin freely, 'crat a little less freely.
(On RW, almost everyone is an admin, but admins have somewhat less powers than on WP, e.g. RW admins can't edit the interface, only 'crats can do that. I would suggest only doing such things on LW if and as needed - KEEP THINGS AS WIDE OPEN AS POSSIBLE TO MAKE A WIKI WORK.)
People worry about admin status lots and lots on Wikipedia. This is because humans obsess about social status, not because it does any good toward writing an encyclopedia - it's an anti-pattern and really shouldn't be imitated.
I don't think not enough people being admins was ever an actual problem that prevented people from doing useful stuff on LW wiki. There's just too little interest. If giving admin status can incite interest, that's good, but I'm skeptical.
So, as people have probably noticed, there's fairly regular vandalism on the LW wiki which has been taking a while to address and which regular users have been trying to cope with by moving and blanking pages. This is a little silly - it doesn't resolve the problem and just generates more noise in the RSS feed for Recent Changes (to which I've long subscribed).
We need more administrators.
I suggest myself. I'm a longtime LWer with high karma, so I can't be too crazy. More to the point, I currently handle vandalism as an administrator on the Haskell wiki and have done so ~July 2010; I was formerly an administrator on the English Wikipedia (where I have been a contributor since ~2005); nor have I abused access that has been given to me elsewhere (eg. my shell account on http://community.haskell.org, the commit bit on the PredictionBook.com repo, etc.). In general, I think of myself as a wiki-savvy and trustworthy guy.
Administrators are created by bureaucrats; there are currently 3. Rather than simply message Yudkowsky or Matt of Trike, I thought I'd make my request public along the line of Wikipedia's Requests for Adminship.
If people object, please leave comments; if there are any other users who would like to be admins (David Gerard comes to mind as someone I know from Wikipedia and would trust as a LW wiki admin), likewise.