I have an HP with an AMD Turion 64 Mobile, 1.58 GHz, 1.00 GB RAM, ATI Mobility Radeon Xpress 200 series video card.
It works alright, but is significantly slower than my wife's laptop (I gave her the good one to keep her interest up).
I would definitely prefer a faster system, but need to be able to play on the road, since I travel frequently. But any decent laptop available now would work decently - but you'll always be wanting more!