As a fellow Sony shooter, I HIGHLY recommend you check out the a700. KEH has a body in stock right now for around $800. It will do ANYTHING the Canon/Nikon will do except video on the d90.

High ISO is NIGHT AND DAY vs. the a100. It falls flat pretty much anything above ISO200. the a700 is good all the way up to ISO 6400. I have posted shots on here to prove that.

Also, before switching brands, check out the Minolta/Sony forum-- www.dyxum.com.

They have IN DEPTH lens reviews too-- before you buy a lens, check there.

Or hell, feel free to ask me, since I guess I the resident Sony expert here.