First of all, it's probabaly safe to say that it will be a good investment, regardless of how you are going to use it. (School, work, design etc.) I'm all up for the 8 RAM upgrade if you think you need it, but for the i7, I'd say don't go there if you are not involved with complex rendering or serious multitasking. i5 will do just fine. (I have an i5 model with 4GB and had no problem for close to 7 months now.)

Just a heads-up, make sure to check the air's wi-fi connectivity when you buy it, as the prime problem seems to be it.

Enjoy.