I guess if you can see a market for a particular ext then there is no reason you have to go with the usual suspects .com .net .tv Whilst all these are the big boys, if you find a niche market lets say in india then with the growth in india you may well look at reg .IN for you names
Also almost every keyword in the .com has gone, but there are always new trends, products, events happening its time to keep your eyes open and bag that 1 name that will make you RICH