I have plenty of memory so I would like to be able to get above the limit in order to do very high res vertex painting.
Is it possible to increase the max allowed value.
Nope… But 80 is per subtool base… so it can be really a lot, if you know how to manage your subdivide and subtools.
Yeah, but that does not help as I need a little more in a single sub tool.
I hope that will be changed and let to us to decide in the future, because I cant really see any point in a limit that is less than available memory allows for.
I guess I have to hope for that in zBrush 5.
Maybe they will go a bit further with 64bit possibilities in that release.
Well, is exactly what I said… You have 80 millions for everyone of the subtool of a tool!
And remember that your computer is not just RAM… The limit is given also cause of possessor, disk speed…
We all have different systems with different power.
What I mean, is that I prefere if it’s left to me to decide if I, based on the system I have, want to go to whatever Milj polygons in a single subtool.
There should not be a generall value forced upon users with powerful systems.
And my guess is that there won’t be in the future, when 32 bit support is left for the history books in zBrush 5.
I’m sure Pixologic will have a very sound reason for capping polygon count at 80 million. Who knows, they may have noticed significant software instability occurring with meshes beyond that number. Remember, this is still a beta version.
Yeah, I know it’s beta.
That’s why I suppose and hope it could work different in zBrush5. 
Background information is good. http://www.cplusplus.com/doc/tutorial/variables/. Finite numbers and ‘limits’ will be ever present in your life 