VMware player had a complicated release history…
Developed in parallel to Workstation 5.5 it was released and annunced as 1.0 final before Workstation 5.5. That was a marketing mistake, since that build is considered beta 2.
Than VMware released Workstation 5.5, embedding a new build of Player 1.0. Even if everybody consider that the final release, it is not, since the stand-alone product was still labelled beta 2.
Now, finally, VMware release a real final 1.0 which has a build number higher than Workstation 5.5. This is an important note cause isn’t clear what users should do with the Player build embedded on Workstation 5.5.
VMware Player is based on the same virtualization engine of VMware Workstation 5.5, with a subset of features.
The world press and the whole virtualization community talked about this product, working on reducing limitations. Related to this you could want check out my Guide to create .vmx files for VMware Player.