I went through an entire little quest series in WotLK (WoW) the other day on my own. It was well-written, well-designed, and enjoyable -- and I completed the whole thing solo -- even a final epic battle part with an elite bosses and so on. All of it soloable.

I like a mix of solo and group content in an MMO, but I get frustrated by the standard "solo quest leads to leads to another solo quest leads to a group quest" format that so many MMOs seem inclined to offer (including WoW, though less so in WotLK than in the original game and TBC).

It's nice to see the industry learning how to make content more accessible and fun for all kinds of playing styles.

This made me happy and it also makes me hopeful for what we might see more of in Cataclysm.