Likewise, thanks for the posts so far - this thread is helping to clarify a lot of dilemmas for me!
I'm in a similar position to many of the posters here: I've lugged a 2007 13" Macbook around with me for the last 6 years now; I now have a golden window of about a month between graduating & losing my student discount, and the release of these new models.
Given the longevity of my current set-up (admittedly upgraded over the years), I'd like a pretty future-proof laptop - and I can see people above suggesting the i7 to 'future-proof' the MBA. But what exactly is this 'proofing' against? I'm still using Snow Leopard, as I don't think my 2GB RAM could handle Mountain Lion, but would a processor really be a bottleneck for future OS updates? I don't really see my own requirements changing much over the next 3 - 4 years.
I'm also interested in the effect of i5 vs i7 on battery life - portability is a big thing for me, and being free of the power brick would be fantastic. But I do routinely run multiple apps - not anything like video processing, but Word, Excel, Papers, iTunes, Evernote, Firefox, Mail, and Calendar all running at once on my current laptop can really slow it down. Again, is this more a RAM issue, rather than a processor issue?
Finally, I've been stuck with (the original) Starcraft and Civilization III for a while (!) now; I'd like to give SC2 and Civ4 (if not 5) a go (and possibly Half-Life 2, now that it's come to Mac at last); anyone know if the i5 would be a barrier to these? (Please don't laugh at me for being about a decade behind everyone else on games!)