I don't think battery power is ready for O gauge yet. In its current state of development, it brings its own set of issues. But I do like the idea of R/C direct to the loco. Unless you're planning on a fully-automated layout with track sensors, computer-controlled switches, etc., I think having a central command base propagating a signal through the track is a disadvantage.
I know of two companies, LocoLinc and Airwire, that offer fully-featured direct R/C systems. Although they are designed for battery operation, it should be pretty trivial to get the decoders to work from track power. If I were going to operate on a complex club layout with tunnels, over & under, closely-spaced yard tracks, multiple blocks, etc., then this is what I would install in my locos. It would operate just fine alongside TMCC and DCS (except probably more reliable!)
Also, I'm not interested in running my trains with a cell phone. I like the fact that both of the above-mentioned systems still offer physical controllers. My $.02.
