I would recommend waiting for the ASUS Zenbook Prime UX32VD if you can. it's $1300, and you'd have to put your own SSD in it, but other than that, it's perfect.
Specs:
13.3" 1080p IPS display
i5-3317U
NVIDIA GT620M
3.17 lbs
7 hour battery life if you stretch it (probably closer to 5 in real life)
1 removable memory DIMM
Removable standard 2.5" 7mm HDD
32GB SSD cache.
My next laptop will be this if I purchase in the next 6 months or so. Even with purchasing a $400-500 SSD, it's $1700-1800 total. Also, the laptop has 2gb of memory soldered to the board and one free slot, so it can do 6gb at least, maybe 10gb if that free DIMM slot can handle an 8gb DIMM.
With the state of the market, this is the best there is. I linked the review from notebookcheck below. I really can't think of another ultrabook better suited to your needs. It should be available with an i7 at release, too.
As far as when it releases in the US, that I don't know unfortunately. I would expect it to show up in the next month or so, though.
http
/www.notebookcheck.net/Review-Asus-Zenbook-UX32VD-Ultrabook.75591.0.html
*This recommendation comes with the caveat that you should be able to disable that SSD cache in the BIOS. If you can't, it'd be kind of useless and stupid. I can't imagine them not putting that in the BIOS for users who know what they're doing, but it is a possibility. If that's the case, then your SSD performance would be handicapped by that tiny, probably very cheap and slow SSD cache.