There is a Onkyo 605 model that is about $400.00 with HDMI 1.3a, and I believe it DOES have DtHD decoders in it.
Things have shifted with the HD formats when compared to SD DVDs. It is now better to decode the HD audio soundtracks in the players and NOT the receivers. As a matter of fact, any HD disc encoded in Advanced Mode CANNOT have the HD audio sent as an un-decoded bitstream anyway. Almost all HD DVDs are encoded this way, and it is expected that once BD players come out that are Profile 1.1 compliant that they will be encoded in Advanced Mode also. This is because the receivers cannot do the audio mixing on the Advanced Mode discs.
Just make sure any BD player you get has the HD audio decoders built into the player, and you are all set. There is no need to worry with the HD DVD players since it is MANDATORY to have them in the players.