Yeah, I've been in that situation a few times. Either another guitar player who isn't as good or one of the musicians in the band who isn't pulling his weight. There's not a lot you can do about it except prove you can do better and they'll naturally turn to you for the solos.
Band situations are tough. There's so much ego involved that it makes things difficult. The thing you eventually have to decide is how serious you are about having a 'real' band and if it's worth it to leave and start something up yourself. Find some cheap rehearsal space to rent, put out ads and notices that you're looking for band members and start auditioning people.
You're not just looking for talent, but the right personality and the kind of person who doesn't need to be told what to do all the time.
I think the best advise I ever read was an interview with Supertramp years ago. The saxaphone player ended up being in the band because he just kept showing up and wanting to play. That's the perfect kind of person you want to work with but really rare.

If you stick with the band you've got now, you'll either have to put up with the situation until somebody blows up and says the wrong thing, or get it out in the open now and say something.