I don't think I could go back to a single or dual monitor configuration. I really enjoy the immersion you get from a widescreen res. If I had to do it all again, I would either get a monitor with a native DP, or go the nvidia route and forget DP all together.
Most games released today are bringing native widescreen resolutions to the table, like Metro 2033 and Mafia 2 for example. As far as the fisheye effect you get, I believe this will eventually be corrected through the software devs the more popular widescreen gaming becomes.
A year ago DP monitors were much more expensive and for most, the dp adapter was the only option. This isn't the case today though. Yes, the technology is still somewhat new but prices are dropping.
AMD is now offering a single link "official" adapter for 30 bucks. It's still expensive for an adapter IMO, but it beats paying $100.
http://www.tomshardware.com/news/DVI-DisplayPort-Radeon-Eyefinity,11201.html