2. The 5900's look to be the top-end cards for quite some time. Without getting too much into tech-talk, it's nigh impossible to make a GTX495 with the GTX470 parts.
Eh, a 470 doesn't pull much more juice then a 280 did, and that didn't stop NVIDIA from making a 295. It'll be made, it'll put up numbers, it will be hot, and be inefficent. Same as all X2 GPU's really.
3. An HD5770 will play all those games maxed out. Unless you plan on upgrading (your monitor) soon, a $150 card will be fine.
Heck, a 260 could max the games he listed, let alone a 5770. Right now, I recommend a 4890 simply due to its lowered price.