I thought i'd give an update for anyone that comes across this - Aug 23, still no lounge.
Given a voucher for the sports bar - gets you two drinks and a rather sad looking buffet.
No charging points and the music is very loud, so you can't make calls or anything like that, actually my flight was delayed by hours and the music pumping at 3AM, 4AM etc soon gets tiring.
That said the Premium Plaza lounge wasn't much to speak of, limited seating, no windows and poor food too.
For all the talk of Air India being the next 'super' airline etc,travelling through Delhi has a long way to go in terms of true 'passenger experience' mentality - while it's by no means terrible, sometimes it feels like they enjoy torturing you eg stupid paper tokens for WIFI if you don't have Indian SIM.
The airport has a very high staff to passenger ratio, but they all seem to work slower than airports with half the staff!
Weirdly BA seem to have cancelled the BA256 / BA257 flights this week. I guess they found somewhere more profitable to fly the planes.... seems unfair on anyone who had a booked ticket!