I am pleased to announce, that its now out there. Some examples of specifying the travel class:

Lucknow to Delhi AC Train
Kolkata to aligarh by sleeper class next tuesday
Jammu to agra by 3 AC on saturday
hyderabad to Jaipur by 2 AC train

Its quite tolerant in terms of how you specify class. For example train class 3A can be specified as 3rd AC, AC, or as 3A.

All the train classes are supported:
- SL (Sleeper)
- 2A (AC 2 tier)
- 1A (AC First class)
- FC (Non AC First Class)
- CC (Chair Car)
- 2S (non-AC seating)

(point to note here is that if a class is not supported by a train we still show that train and try to show a class which is close enough. For e.g. if somebody wants 2A and its not there then we may show a 3A class as default if 3A is there in the train)

The flight classes supported are Economy and Business.

Classes supported in a Bus are Seater, Sleeper, but  the search end its not implemented.  Meaning even if you specify a class for bus travel, it will ignore it, as of now. But on our results page we do show you the supported classes by the Bus Operator.

Try it out! Feedback very welcome.