PEEP SHOW (FOX) - Rachel Boston ("American Dreams") has joined the cast of the comedy pilot, described as a look inside the disturbing minds of two roommates (Johnny Galecki, Josh Meyers). Amanda Holden also stars. "Peep" comes from executive producers Jeff & Jackie Filgo and the Carsey-Werner studio.

From:
http://www.thefutoncritic.com/cgi/gofuton.cgi?action=newswire&id=6831

This doesn't look good..... :( :( :( :( :( :( :( :( :( :( :( :( :( :(

She is not a regular on the show, none of the cast have been let out of their American Dreams contracts yet- so don't worry!

Someone on another board said that just because she's signed on to do the pilot, doesn't mean that it will make it on the air. There are alot of pilots that aren't accepted by the networks, and even if this one is they've been known to recast certain roles. This is a bad example, but if you watch the pilot episode of 'Roseanne' I believe there is a different actor playing Dan and Roseanne's son DJ. He was replaced by Michael Fishman later.
I think Beth was a recurring character during seasons 1 and 2, but this season Rachel Boston was added as a regular, probably since Beth had JJ's baby.
The actor who plays Uncle Pete, for example, is listed as a guest star, although he might as well be a regular because he's on quite frequently.