In case you've been living in a cave
Well, I like the color and it looks good in black and white/grayscale. Also, it seems immediately "branded," so I don't imagine there will be much confusion when web-savvy folks see the logo.
It kind of looks like a 'S' and the smaller the logo gets, the more it looks like an 'S'. Logo's are supposed to scale well, I'm not sure this one pulls that off. Also, it reminds me of the Slomin shield.
Simply put, it isn't. I don't find anything outright ugly or displeasing about the logo. Furthermore, it looks like it belongs on the web; like it belongs to a website. It has that web quality to it that seems to define a well-designed webapp logo. As it should, after all, it is a logo for a web technology.
By the way
I don't claim to be a logo designer or analyst but this seems like something worth talking about. So, take my opinions with a grain of salt, though I don't really think that disclaimer needs to be explicitly stated on a blog...
HTML5 has a logo now.