With the release of the OSGi 4.2 Enterprise Specifications, the number of OSGi specs has improved dramatically. This is a good thing because many more use cases are now covered. Is it getting bloated? Not at all, as with OSGi you only take what you need. The basis is always something that implements the OSGi Core specification, and these implementations are often very small. Apache Felix is 383kb and Eclipse Equinox is only just over 1MB. If you need to use any of the other specifications you can add them to your framework runtime to just provide you what you need. Nothing more, nothing less.
To my surprise it was sometimes fairly hard to find where a certain OSGi spec implementation could be obtained. Most people know where to find a number of core frameworks, but where to I find a compliant OSGi Web Applications implementation? Or a Remote Services one? Or maybe you're not happy with a particular implementation, where do you find an alternative?
So I started putting together a list of OSGi spec implementations on Wikipedia, both for core frameworks as well as for other OSGi specifications such as the Enterprise ones.
The wikipedia page is here: http://en.wikipedia.org/wiki/OSGi_Specification_Implementations
I'm sure the list is not complete and there may be some mistakes in it, so I would invite anyone who has more information to add it in!