I have never had any doubt that .co.in/.in domains are a very worthwhile investment. I have personally over the last four years had sales that are now edging towards $200K,a large proportion to resellers but also quite a few end user sales. I think it is the region of 800+ names that I have sold from prices ranging from $xx to $xx,xxx, the majority were .co.in.
I still retain a fairly good portfolio of both .co.in/.in.
I am confident that will only gain even more popularity.
Incidentally,about 3-4 years ago I was derided on another forum when I estimated the value of my .co.in/.in portfolio to be around $300K. Fortunately it appears that it was an underestimate!