It seems that Gmail and Windows Phone 8 do not play nice with one another, never mind that they are on HTC or Nokia hardware. There are reports being bandied about that synchronization issues with both Gmail and Windows Phone 8 end up with the email client crashing, and if you are curious, you can check out the People Hub as well as the related linked contacts from Gmail in addition to the email application itself. For both cases, the affected devices will remain in a perpetual state of synchronization. For instance, the email application will see the synchronization continue while the app closes, meaning the constant state of synchronization would end up with your battery being drained severely. Perhaps if you noticed how your new Windows Phone 8 device does not seem to have a decent battery life, it could be due to this issue with Gmail.
There has been no way to track down the source of this bug at the moment, but perhaps the most recent update could have caused it. Hopefully someone will be able to come up with a fix pretty soon, otherwise it is going to be a black eye on Windows Phone 8 as Gmail is not any service, but it is a major one that plenty of folks use in their everyday life.