I am in the same boat.
I am prepping our VMware environment for a Trend Micro AV solution. Trend says that vShield Endpoint needs to be at 5.1.2 or 5.5 to work.
Well I'm stuck I can't upgrade to 5.1.2 or 5.5.
I have upgraded my vShield Manager appliance to 5.5.0a (latest as of this post date). I'm running vCenter 5.5 and ESXi 5.1 on the hosts.
The only options I have is to go from 5.1.0-833297 to 5.1.0-1255202 on vShield Endpoint.
I have since done so and now I don't have an 'upgrade' button anymore showing up in vCenter implying I am at the latest vShield Endpoint.
I have been working with VMware support on how to get Endpoint to 5.1.2 or 5.5 but they have thus far not provided a path. They are saying that there are some issues with vCenter 5.5 where incorrect versions are being reported in the GUI. Great..so I have no idea where I stand.
I think I've reached a wall and have no choice but to try to install Trend and 'hope' it works with the version of Endpoint I am at.
If anyone has a fix or any info please share!