Getting accepted into a top level CS program.
tjr: I received my bachelor's degree in 2002.  I've been pondering graduate school on and off, and have done a bit of graduate study online.  While I can't speak from the position of someone who is currently there, I can offer this with regard to your first point...It's been nearly seven years for me now. I've stayed only  slightly in touch with one of my undergraduate professors. I feel that getting academic recommendation letters may be difficult at this point.  If you're going to wait, I would suggest maintaining conversation with the professors most able to write letters for you.