In short, yes.
It depends exactly what you think you'll be able to do but essentially you'll have two monitors running off the same system. If they are
both 720p or 1080p then you can have the desktop mirrored on both screens. Use an RF keyboard & touchpad with plenty of range (or an IR extender) and you'll have full control from both rooms. Think of this like displaying a presentation on a projector, whilst you look at it on your laptop screen. It's exactly the same.
(This is assuming that the mobo will let you use dual displays (or even triple if you also have a DVI output) but every card I've had since 1997 will do that so I really doubt it'll be an issue.)
EDIT: it's not an issue with your mobo.
http://www.amd.com/us/products/notebook/...6300m.aspx
If you've got one 720p and one 1080p TV (like I have) you won't be able to have desktop mirroring (and extending the desktop would be a silly idea), but you could switch one TV off and the other on and Windows should auto-detect which screen is on at the time and adjust the screen resolution automatically. What I can't tell you is how XBMC will react to this but I can't see it being a problem.
And if you're VERY clever about it, if you add a separate sound card, you could set up a Disney video for your kids to watch in one room whilst you browse the internet for pr0n in the other room. I wouldn't advise this though - but you get the idea of what's possible. Needless to say, what you can't do very easily is
control the HTPC simultaneously from both rooms. Although it's possible - I guess you could feasibly control XBMC with a MCE remote and the rest of the PC functions with a keyboard/touchpad/mouse.
