Hey,
Just want to share some experiences, i mostly do my sprites for 2D Style game using Photoshop, so far i didn't found any troubles using it, all is well and perfect. but again i have to agree with the moderator that using PS can be quite time consuming as you wont have basic "onion skin" to work on (unless you do it manually by changing the opacity of the top/bottom layer).
conclusion is, its doable!

here a sample chara I've done in PS :
