Older products like VSE use V2 dats Products like WSS use the newer V3 dats.
In both cases the actual .dat files themselves are unsigned.
Various files in the associated packages especially in V3 dats are signed. The executable installation package or "Xdat" in V2 is also signed.
McAfee Products use an internal verification mechanism as well as the standard certification verification methodology to ensure that updates are trusted and we have at this time just updated the content in this beta so that the products will recognise the new certificates when they start to be used. Obviously this first stage needs to be completed before the new certificates can be used.
Because this mechanism is internal there is no simple way way to verify the change but we are giving customers the chance to satisfy themselves that this internal change is completely transparent to them before this goes live.
There will be a second beta period shortly where the signing will be changed on the appropriate files.
I hope this helps to clarify the situation