I checked JVC's site and there is no mention of 60P playback capability on the BR-HD50U. Is this true? Am I required to use the HD200 as a feeder if I'm shooting 60P?

Should have done a more thorough Google Search first:
http://pro.jvc.com/pro/pr/2006/releases/hd50_upgrade.html

It just needs the v1.06 (or newer) firmware update, which is free and downloadable. All BR-HD50 units that shipped since last year or so should already have had that update.