The only “purge” I see is the Establishment wing of the GOP (read RINOs) trying to marginalize conservatives except at election time. The Tea Party put the GOP back in charge of the House, yet the House leadership has excluded the Tea Party Congressmen from leadership positions. It is a travesty and will eventually lead to a third party. The conservatives are the ones who are being purged.
Freshmen are rarely if ever given leadership positions. Most don't want them. They're too busy trying to get their feet under them trying to figure out their new jobs, trying to get their offices up and running, finding a place to live, learning their districts, etc. It's going to be a very rare instance where a freshman will be allowed to jump the seniority line to take a Committee chairmanship or another leadership position. It would almost have to be as a result of a game-changing party switch for something like that to happen, where one person changes which party is in the majority by switching. They may hand out the occassional deputy whip position to a freshman, but even that won't happen often. Too many toes would be stepped on to move a freshman into a leadership or Committee chair position--and they're frankly just too inexperienced to know how to function effectively in those roles. Maybe you'll think that's a dumb way of doing things--but that's how it works and there's some reason to it. Don't worry, the class of 2010 will move into leadership positions in the years to come. But the fact they don't have them yet isn't really anything to ding the GOP House leaders over.