If you wait about 6 months, Apple will most likely release rev. 2 of the ARM based AppleTV, which is rumored to contain the A5 processor, which is based on ARM's dual-core design A9 architecture, and is supposed to be fully capable of hardware accelerated 1080p playback.
The newer hardware should be much more future-proof. It remains to be seen whether it will be easily jailbroken, or whether Apple will get tougher with security.
The newer hardware should be much more future-proof. It remains to be seen whether it will be easily jailbroken, or whether Apple will get tougher with security.