The first boss in ulduar isn't very gear dependent, you're in vehicles. You do need some gear since the vehicle HP is determined by the ilvl of the gear that you use, but you don't need to have full epics to make it work. In 10-man, two characters do some out-of-vehicle fighting, but the gear requirement there isn't too much and the combat is easilly macorable to just spam one button (/target whatevertheturretiscalled, /cast dps). After that you have a choice of 3 bosses. One of them is definitely doable, one of them I'd be very impressed if someone solos it but it's probably not too bad if you have a couple people helping, and the third I haven't done yet but from what I read it looks like there's a little too much going on at once to solo it. Beating the enrage timers is also something that you need to consider, you can't let your dps have downtime.