.UK and .GB are likely to not come out any time soon if ever. If they do it's likely the .co.uk domain owners will automatically get first picking of the .UK of their domain.
.co.in is going to slowly lose value as .in becomes more popular yes, so NNN.co.in isn't a good investment.
Premium three letter ccTLDs of countries with a reasonably high living standard and population of 5 million and over is my favourite bet as they have good end user value. ABJ.ch was available a few days ago - I'd rather buy that than the 5 NNN .co.in's I could get for the same price as it has much more end user potential as there could be a company or organisation that is founded in Switzerland with the initials ABJ and is willing to pay a few thousand US$ for that domain. If it's still available and someone isn't as massively in debt as I am go register it
