I wouldn't expect them to ever be "standard," or if they do it will take quite a few years. If the rate of adoption of Dolby EX and DTS-ES Discrete is any indication, 7.1 TrueHD and DTS-HD tracks are going to continue to be intermittent. When the HD format war started, there were a number of comments suggesting that interest in mixing such tracks was low - bordering on outright resistance to do so - in the industry because it wasn't being used in the theaters and thus required creating two separate multichannel mixes (one at 5.1 for theaters, one at 7.1 for video release). I haven't seen much talk about that in a couple years, but I would suspect that the issue of investing time and effort in additional mixing work would still hold true and would most impact movies with less successful box office results. (Take Speed Racer as an example - it's BD release is reported to be a BD-25 with basic Dolby Digital audio, not a higher-bitrate transfer on BD-50 with a lossless audio track, and the decision to do so is generally being attributed to SR's poor box office take.)

For folks using HDMI for their Blu-ray audio, it will often be possible to use matrix processing modes like Pro Logic IIx to expand 5.1 tracks to 7.1, but for folks using multichannel analog it remains to be seen what player manufacturers will do for us. Even 7.1 analog outputs on players remain a bit elusive, but in theory a player with 7.1 analog out and onboard decoding could include Pro Logic IIx or something similar and be configured to automatically engage that when a 5.1 track is being played. I haven't seen it yet in Blu-ray hardware, but OPPO already did it (with a basic steering logic rather than PLIIx) on their 980H and 983H players.