[THIN] Xenapps 5.0 for Windows 2003

I have seen posts on this and I know it’s probably been discussed but someone please lay it out for me…..I am currently running PS40 on Windows 2003 and have a need to go 64 bit on some of my servers…I have been waiting for Xenapp 5 to be released but now I understand that to get the “real” 5.0 version you need Windows Server 08….Our organization is not ready for Server 08 from an OS and from a TSCAL licensing perspective...Am I to understand that Xenapp 5 for Server 2003 is really Xenapp 4.5 at the core?  Is the version downloaded “patched” up or do we need to install hotfixes and HRP as though it was 4.5 to begin with?  Is licensing different?  How do I get the Edgesight plugin that enhances RM?   This whole thing confuses me as I was expecting a branded 5.0 version for 2003……Any explanations are appreciated….