I think he'll reach double digits. How far can he go from there depends on a lot of factors. If Nadal doesn't come back strong, he will probably win 2 Roland Garros. I think he should win 2 more in each HC slam and maybe he can fluke another Wimbledon. Federer will not be around for long, he already beat Nadal there and he may beat Murray I think, although he wouldn't be the favorite.
There's no Dark Side of the Moon really, matter of fact it's all dark.