I use the L 2040 fund, and i agree that it's becoming uncomfortable conservative. I've been using my IRA and after tax accounts to keep my overall allocation a 10% cash, 10% bond, and 80% stocks. There's no real reason to change my TSP allocation, but I find myself wanting to play.
If I do switch funds, I'll to to 2050, or 2060. I could invest in individual funds, but eh.