Because no reference like "unsupported" can be found in whole vCenter 5.0 documentation we can assume that YES.
I never had any problems with special characters in vCenter 4.x and 5.0 ...
Issues with special characters in passwords comes with arrival of vCenter 5.1 and SSO service, same for 5.5
Also beware of using special characters in VMs and datastore names in vCenter 5.x
Troubleshooting issues with virtual machines or datastore names containing special characters (2046088)
http://kb.vmware.com/kb/2046088
For vCenter 5.0 and ESXi See:
Prerequisites for the vCenter Server 5.0 Upgrade
http://pubs.vmware.com/vsphere-50/index.jsp?topic=%2Fcom.vmware.vsphere.upgrade.doc_50%2FGUID-093777CF-BB5A-4D23-A41D-5B791789E33C.html
Upgrading to vCenter Server 5.0 best practices
http://kb.vmware.com/kb/2003866
Other sources:
ESX and ESXi 4.x and 5.x password requirements and restrictions
http://kb.vmware.com/kb/1012033
Host Password Strength and Complexity
http://pubs.vmware.com/vsphere-50/index.jsp?topic=%2Fcom.vmware.vsphere.security.doc_50%2FGUID-942E8E23-D2CE-49B0-8B39-F31EF6D0519B.html
Password Requirements
http://pubs.vmware.com/vsphere-50/index.jsp?topic=%2Fcom.vmware.vsphere.security.doc_50%2FGUID-DC96FFDB-F5F2-43EC-8C73-05ACDAE6BE43.html&resultof=%22special%22%20%22characters%22%20%22charact%22
If you want a bulletproof answer you can contact VMware support for acknowledgement...
Regards,
P.