foo!(bar) ==> foo{bar}

[Sandeep K]

I don't like {} at all. {} should be for function bodies, lamdbas. 

Here's a thought:
By default make all templates belong to a reserved namespace. So prefix the namespace when you need to disambiguate. Call the namespace "T" or "template" or ? 
T.foo(T.meow())
All templates in the current namespace say Cat get collected under Cat.T 

Might look bad but I don't think any of the other solutions look that great either. This syntax looks a lot more uniform to functions.