Your post and sig convince me that you don't have one of the new MBAs. If I am wrong about this, please say so.You'll also get more storage and longer battery life with the MacBook Pro. I would go for a MacBook Pro if it's going to be your only computer. To me it's more of a desktop replacement while the MacBook Air is a computer when you're not at home.
Until I got my MBA in October, I had always subscribed to the notion that no MBA could serve as a desktop replacement. I was wrong. For nearly three years before I got an MBA my primary computer had been a 17 inch 2.4GHz Santa Rosa MBP with 6 GB of RAM. On it I ran Windows 7 in Unity mode and customarily had a couple of Windows apps and 5 or 6 OS X apps running on the OS X desktop 24/7. Before I got the MBA I was concerned that I wouldn't be able to do on an MBA with 4GB of RAM what I had done on the MBP with 6. I soon discovered, though, that, thanks to the MBA's lightning fast flash storage, it runs the same suite of programs the MBP ran with just as much speed and stability as the MBP provided. The result is that the MBA has become my primary computer.