My wife has had an ASUS Eee PC 1000H netbook running XP for the past three and a half years from when it was new, and we have often taken it on our travels. I have also used it a couple of times for work, and it is perfectly fine. Battery life is strong (6 to 8 hours powered up depending on usage) and it does with ease all that you describe. The only weakness in what it gets used for is video streaming. Over Wifi, iPlayer SD is the reliable limit whereas either of our laptops will stream iPlayer HD over the same 801.11g WiFi connection in the same location without hiccup. I changed the WiFi card and performed all manner of recommended tuning, and whilst some of this has helped, it can't disguise the limitations of quite basic architecture.
My professional occupation requires extensive travel, and my employer recently replaced my trusty - but heavy - Lenovo T61 and extended battery with a much lighter Lenovo X1 ultraportable with solid state disk, and for long haul flights without seat power, a second, thin, "slice" battery that clips underneath. It is a fabulous machine that does what I ask of it with blistering performance and without doubt the best keyboard I have ever used on any computer, but then the cost was over six times that of the £299 ASUS.