I am looking at Nexus 3.00 OSS Edition.
The recent release of Nexus 3.0 (OSS Edition) seems to have dropped support for rpms.
I don't see any specific note declaring that they are going to be dropping some features from 2.x.
So i am not sure whether the rpm/ yum repositry support is actually removed Or is it being supported differently with the new Nexus 3.0 or this feature has been made exclusive for the Paid version.
Not yet. The progress of this can be tracked in http://issues.sonatype.org/browse/NEXUS-10191. Feel free to watch for release details.