I need something a little more portable so I found out about the Canon EOS M mirrorless camera that comes out this October.
I've had the fortunate opportunity to shoot the EOS M, it's a great camera for someone like yourself wanting portability and DSLR. The one drawback I found with it was the lack of physical controls, especially the touch screen controls during bright sunny days and no view finder.
I know your under a budget. In my opinion I felt Canon could have provided more of a camera for $700.00 vs what the competition is offering. I choose a Sony NEX-7 to meet my needs of portability, high ISO etc.