The low consumption transponders for Gliders are avail already (e.g. Fielser) and you only need an extra battery or a solar panel on top of the instruments to feed it for 8-10 hours. Not a problem.
The real problem is that it is not mandatory , (but will be from 2008 in EU (2009 in France ) do not know the US mandate date, and it will be Mode S , not A+C.)
TCAS is only mandatory for transport a/c above 19 seats in the US so the bizjets are exempt, so no such luck in that case , even if the glider had an SSR. .
As far as the eletronic on board gliders, our club has just ordered the last LX model with GPS moving map and the lots, nice stuff, but I find it keeps you heads down far too much and not looking outside enough.
Class E airspace and small class D CTRs are growing everywhere in Europe to so call " protect " low cost jets operating into small provincial airports.
But this is a false impression of security. While in Class E ( having left the airway and before entering the CTR is the most dangerous part.
Having seen the number of " misses" so far in Germany and France , It is only a matter of time before we get something serious.
For the IFR jets, Avoiding bases of Cu , seriously reducing speed and looking outside in that part should be the strict norm, but seeing the speed at wich certain LCC 737s operate, I wonder if the message is understood.