Hi, I'm the guy who did the art for this litle collect-em-up. Thought I'd drop in to defend Photoshop which I use for all my pixel art.
The latest version of PShop come with a program called ImageReady which is geared towards creating low res images and animated gifs. Once set up correctly with the anti aliasing options turned off ImageReady is as valid a medium for pixelart as any. Just look at Eboys site, they use Photoshop and create some stunning pixelart.
Anyway more of stuff can be seen here...