Humsafar and Tejas are LHB coaches only, but some facilities have been added to these coaches. Here is a list of the features ( not exhaustive though)
Humsafar coaches will have seats with new, more comfortable padding design for seats, and better headrest design for the upper berths, bio-toilets with odour control systems, Fire and smoke detection systems and alarms, CCTV for surveillance, GPS based passenger announcement system and overall, more plush interiors. And the new vinyl scheme that everyone's talking about. :)
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Tejas coaches are AC CC/EC coaches with more facilities. These will come with entertainment screens for passengers ( screens embedded into the seats like in planes), Phone holder and charging sockets ( again, part of the entertainment screen), on-board wifi, coffee/tea vending machines, Magazines stands and snack tables, Fire and smoke detection and suppression systems, Bio toilets with water level indication, Sensorized taps ( not sure about the exact system, could be proximity or touch based), Digital destination boards, LED indicators for conveying passenger information, automatic closing doors ( not sure about this one, just a guess based on the pictures of the Tejas rake).
Antyodaya trains have the Deen Dayalu coaches. These are normal ICF coaches, with improved seating ( read better padding), Bio-toilets with indicators for toilet occupancy ( commonly seen in AC coaches), RO system for providing drinking water on board and a fire extinguisher among other things.
Overall, the facilities have been enhanced quite a bit, especially in Tejas coaches, which look very attractive for passengers traveling in the premier classes.

Antyodaya is a welcome concept ( Yes, it's just a renamed version of Jan sadharan, but better) and it's good to see some improvements being made to the low cost/unreserved sector other than simple capacity improvements.
Tejas (Renamed version of Shatabdi) will be a hit if our RM fulfills his promise by running them at the proposed speeds, though that doesn't look likely looking at the current schedules. IMO,given the facilities, they can be successful for 6-10 hr intercity journeys if they are run at the promised speeds. Of course, Shatabdi trains can be upgraded by providing them with Tejas rakes, but a price hike would be put up anyway irrespective of the name, because of the...
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on-board facilities, so a name change doesn't really matter much here.
Humsafar is a rather weak case as the enhancements in these rakes are not as fancy as Tejas, and are mostly regarding the safety and maintenance of the coaches. As such, a 20% fare hike for these trains will not go down well with passengers as there are no visible changes in passenger comfort. Again, their hope only lies with fast schedules ( which again, doesn't look likely.
IR seems to be on the right track in terms of improving on board facilities, but again it should be accompanied with better speed and maintenance of standards. Doing just one of these 3 things and ignoring the other 2, will just make these new trains another failure.