You can use Twonky and Bleess to "AirPlay" to your Roku. Bleess works great but only available for iOS devices and not Android. Twonky has some limitations. Just know that you can only "AirPlay" to Roku from "Mobile layout websites". For example: m.filmon.tv. Does not work well on regular sites. You can also consider Plex to stream from bookmarked sites from your Plex server. I personally like Bleess app so no need for me to consider an ATV device. I use Plex, PlayOn and VideoBuzz for YouTube so AppleTV is not worth it. It has lost its edge to Roku now that Roku can "AirPlay" like the ATV.
Consider a jailbroken ATV2 with XBMC but you can use Roku with Plex/PlayOn and unsupported scripts for your "1channel" solutions and other content. Roku with Plex is a lot cheaper than a Jailbroken ATV2 solution.
(2) Roku2 XS, Roku 1 (New), Logitech Revue Google TV, Raspberry Pi, Mac Mini HTPC-EyeTV DVR+Rabbit TV, TiVo Premier,
Wii, PS3, Sony Blu Ray with streaming apps, Equiso Android TV
Local TV: QAM from ISP coax line. PLEX with unsupported plug-ins