Reasons Roku is better:
- Amazon On Demand Video (including prime)
- Plex (for streaming media)
- AppleTV has iTunes, but I really don't like iTunes and don't own any other apple products
- Loads of other channels
- AppleTV is really lacking in the channel market
- Less expensive, get a refurbished XD for $65!
- Simpler menu structure
- Apple seemed to have too many layers to get to a movie (particularly Netflix), I felt I had to click too many times.
If you have other Apple devices, you may prefer the AppleTV for it's integration, but if you don't, don't waste your money - unless you plan on modding it with XMBC when it's available (most likely what I'll do).