Already own a MBP, need a thinner lighter machine to learn how to code "on-the-go", considering getting a MBA...

Hi folks,

I own a 2010 MacBook Pro 15'' 2.2 Ghz i7 with 8GB RAM, a AMD Radeon HD 6750M 1GB, and a 750GB HD. Needless to say, it's pretty powerful. It's great to use around the house, but when I'm on-the-go, it feels a bit bulky.

I am considering getting a Macbook Air...is 11'' too small? Must I really go with the 13''? Is it true we won't see new MBA until June 2013?

I just need something really small and light to spend many hours learning how to program, use Khan Academy and Coursera when I'm at Starbucks.

What are your recommendations? Should I just hold off until the next macbook air next year? Hopefully the SSDs will go down in price by then...

ps. what about the next-gen 13'' macbook pro? Will be thinner and lighter, maybe not as much as a macbook air, but at least it'll have a 500GB HD...I assume it will come out in Feb/March 2013?