Come on shellyp, the Xbox 360 has a lot more hardware including a harddrive which it will need to buffer that HD content. The Roku can support HD display-wise but there's no way currently they can stream it to you over most home links - especially given that Comcst is already capping speeds.
So give them some time. Probably it will take some new compression technology to make it work for the Roku. Anyway, what you already have is an outstanding deal. $99 for near DVD-quality content....come on, we have nothing to complain about!
Cheer up and bide your time.
I wrote my note before Roku responded. Basically I take companies at their word. When a company says, we will support HD when Netflix provides HD, I believe it. However, I'm amenable to support for HD by year end. The timing isn't much different.
I'm more concerned about AT&T's broadband capping, as I use AT&T DSL, and with the caps mentioned, I'm not sure I can run Roku/HD if it's released.
I'm beginning to think internet-based video is a pipe dream, and 2008 will be the last time it's really feasible in the US. Disappointing.