Very true, you have to keep the mouse handy for some games like Skyrim and Battlefield 3. I'm tempted to look into a mouse emulator for the control pad. Should be built into Windows as standard really but it's a good idea so I wouldn't expect Microsoft to implement it.
I have a tiny keyboard with touch for the mouse keyboard needs, works fine. I just need to upgrade the laptop that is my current htpc, having a hard time finding a small low non full size enclosure that takes full size graphics cards.
But it runs Lego games so far, with steam in offline mode