Probably considerably more, basically depending on how many unicode variations that would render into graphically similar latin font characters of G,g,O,L,l,E,e and then you have all the permutations.

So that's probably a few 10,000's overall and then you need to register them for every top level domain that Google operates in so, com., de., co.uk. etc...

Overall there are probably a like 100,000's domains that can be registered, under Google.tld_x alone, more if you count in all the other services they have.

It will cost a small fortune for an individual even in bulk registration prices but still it's more than affordable for a company the size of Google.

That said using cyrillic is even better http://www.miсrosoft.com doesn't looks any different than http://www.microsoft.com but it translates to http://www.xn--mirosoft-gch.com/