I was thinking of doing exactly this.
Thing is, if I buy a Sony Bravia I'll probably situate it two times times further away from me than my current monitor is.
I heard if someone did that, then that's when the HD TVs are at their best, delivering better quality than monitors.
I'm currently tossing up between 30" Samsung (~$1500AUSD) and a Sony Bravia WE series (~$2000AUSD).
The plus-side is that if I do get a Bravia I can hook up my consoles at the same time and watch Bluray from my bed.
I'm not very savvy when it comes to these sorts of things (screens, at least); what size PC monitor delivers 1080p?