Why can't we see Stack Overflow numbers and stats from meta profile. If I try to open a users profile in meta, I can only see his stats relating to this site and nothing about Stack Overflow. I think it's equally important to be able to view all stats and accounts from any of the stack... sites.
Click on the 'accounts' tab on the right-edge of the user's profile page. You'll see all of the accounts on other Stack Exchange sites (including SO) that the user has associated this account with. Bear in mind that a user can choose to not associate their accounts on different sites together.
If you do this on your own profile page, you'll also see options to associate / disassociate your own accounts.