I really tried to make it work. I successfully whittled down my music and photo libraries down to the bare minimums – eventually moving my main iTunes library off to a desktop computer (music sharing is a beautiful thing). Living with a 80GB hard drive, which formats down to less than 64GB, isn't as hard as I thought it would be. The smaller 13.3-inch screen (compared to my MacBook Pro's 15.1-inch) was also a concern at first, but I overcame that pretty quickly. When I needed something larger I'd connect to an external monitor on my desk.
It wasn't the MBA's lack of ports either. It turns out that I really didn't miss FireWire as much as I thought I would. Most of my external FireWire drives also have USB 2.0 ports and I don't do any real video capture. Podcasting is another story altogether. It's made difficult by the MBA's single USB port and recessed headphone jack. If you prefer a direct Ethernet connection, it's impossible to use both the USB/Ethernet adapter and a USB microphone (like the Blue Snowflake). The MacBook Pro is a much better choice for podcasting.
In fairness, I've made some changes to my day-to-day routine which have made the MBA less practical for my situation. Rather than commuting to work every day, I now work at home, eliminating a major benefit of the MacBook Air – its portability. I'm not ready for a desktop Mac though, I still travel – just differently. Usually from desk to couch to dining room table.
My biggest problem with the MacBook Air has always been performance. I would too often run into the beachball and molasses-like performance when I had a dozen browser windows open. While I don't need the world's fastest Mac, I need one that can have lots of browser tabs open, NetNewsWire checking 500+ RSS feeds, Mail, Adium, Photoshop, BBEdit and iTunes running. The MacBook Air simply isn't up to the task.
While you can run all of the above on a MBA, it's not really usable. I have the 1.6GHz processor configuration and it would often grind to a complete halt for minutes at a time. The bigger limitation however was the MBA's fixed 2GB of RAM. While sufficient for light duty, 2GB isn't enough in today's age of RAM-hungry software. And if you use virtualization software like Parallels, VMWare or even Crossover, 2GB won't cut it – you need at least 4GB.
My machine of choice these days is a MacBook Pro 2.4GHz (Penryn) with 4GB RAM. The straw that finally broke this author's Mac was the recent release of the 7200RPM, 320GB Scorpio Black hard drive from Western Digital. Adding the new, faster drive that to my MacBook Pro rig really makes it scream. I can't wait for the 500GB, 9.5mm drives to start shipping.
While this isn't an indictment of the MacBook Air, I think that it's a capable machine, just a capable second machine.