Does this mean IBM will be suing Oracle? and would Oracle go against Microsoft as well?
This is an interesting problem, though. Do APIs have non-zero inventive value? I would certainly say so, yes. In my opinion JAVA's popularity and adoption had a lot to do with the the very well thought of API of JDK (at least most of it). I know, I have used other APIs that lack consistency and thought process and that troubles my core!
Now, the question could be whether SUN put this in public domain or not. Apparently so; JDK v1.0 was release in 1996 android v1.0 was released in 2008, and even before that Microsoft had (almost) copied Java API to .NET platform (The most glaring change they did was StringBuilder from StringBuffer!). SUN did not go after Microsoft, and SUN did not go after Google.
In my opinion, APIs should be protected by copyright. But I'd say from now on. I'd not apply this retroactively. I'd want copyright laws need to be amended, so that any vendor releasing APIs for industry adoption reasons must explicitly release the API in public domain.
Having a well thought of API is such a valuable thing that we need people to think them having significant value and and thus spend significant effort defining them.