I am a hardcore atheist but I will start believing there is a God if Kate Michuchi stays in the show as Raj's girlfriend.
OK, OK, I am too much a hardcore atheist to believe in God no matter what, but Kate Micuchi as Raj's Girlfriend would be the next thing to divinity. Perfection would be that also her partner at Garfunkel and Oates (Riki Lindhome) would be Raj's other girlfriend (what could be more funny that the poor loser suddenly has a permanent threesome).
Please, make her stay.
The episode? Ah, funny as usual (although sometimes I want to enter the screen and punch Sheldon in the face for being so mean with Amy)