I'm a professional writer and the Air is the finest Mac I've ever owned. Were I a professional audio producer, it would be the worst. It's not so much the power -- although faster is faster, and when you're working, you know, time is money -- it's the abbreviated internal storage and lack of multiple interface ports, and any FireWire port at all, which keeps you from using numerous FireWire audio interface, such as the Duet and others. And from friends I know who do professionally produce music and cinema audio, USB audio interfaces just don't cut it, perhaps not merely because they're USB not FireWire, but because they are consumer or hobbyist devices rather than professional tools, they are USB-only.
But for fun, say GarageBand, as an amateur hobbyist, no problem. Bear in mind the Air doesn't even come with all the Apple Loops and whatnot installed -- they're on the install DVD, just not installed to space -- so you'll have to allocate your internal storage accordingly.
Quick question...I am not by any means a cpu savvy person. But I'm looking into getting a MBA. I do pretty basic things like youtube, internet, music...the usual. I am a musician, just hobbying as of now, but I do know that at some point I'll want to get in Protools/Logic. Correct me if I'm wrong, but I've heard ppl say that they'll just use the Time Capsule to sort of compensate for the lack of hard drive on the MBA. Is it possible to run the Protools or music software from Time Capsule?
Frankly, after 22 years of using only Macs, the Air is the first Mac most targeted toward academics, students and writers, over those in the visual arts, like graphics and film, or the audio field, music and sound effects for example. Small and light is great for constant travelers, but constant travelers in these other fields who must work while on the go can deal with MacBook Pro or MacBook. So can writers, scholars, researchers, etc., but the feel of snagging a thing thin and light as paper notebook out of your bag, instantly opening it to where you left off, rather grabbing for your laptop computer, is something people in these latter fields find more accessible, in fact is one of the reasons many writers carry paper notebooks in their pockets or bags, but have a laptop they leave at home on their desks.
But for the hobbyist in audio and music, the Air is plenty. Get the external SuperDrive drive if you want to burn CDs of your work, eliminate the sneaker-net-esque hassle of copying file to another Mac to burn a disc, and I think an external USB2 hard drive is a must for back-ups and archiving projects.
p.s. Pardon typos. It's Easter. I'm celebrating by not nitpicking every trivial thing I write.