I'm not so sure the Enterprise featurettes were shot in 4:3.
They were presented to us on DVD in that format but they were in fact shown in letterbox 4:3.
I just watched Disc 7 of the Star Trek: Enterprise The Complete Third Season - 2003-04
DVD. It had the special features including: The Xindi Saga Begins
(13 mins), Enterprise Moments: Season Three
(13 mins), Enterprise Profile: Connor Trinneer
(17 mins) and A Day in the Life of a Director: Roxann Dawson
They were all shot widescreen. I could not tell if the look was Digital Betacam or HDCAM/XDCAM HD [but it did
have a digital videotape source look (Not analog BetacamSP widescreen). If they were indeed shot on HDCAM/XDCAM HD then they along with the special features for the other 3 seasons may have been shot and edited in HD and could be
presented in HD for the Blu-ray release.
If you haven't seen it A Day in the Life of a Director: Roxann Dawson
really was a cool behind-the-scenes 17 minute feature just like if you were on a Trek film set. If Paramount had cameras on the set of Star Trek XI
with this level of quality on a daily basis then I'm really
looking forward to the Star Trek XI Blu-ray
I am going to move up my Enterprise season disc's 7 up to the top of my Netflix Queue to see the rest of Enterprise
's behind-the-scenes featurettes.