Poland and Ukraine are going to make a joint bid for Euro 2012, see this link (in Polish): http://www.pzpn.pl/podstrony/aktualnosci/1.php?id=8458&kategoria=1 and this link (in Russian): http://www.ffu.org.ua/news.php?news_id=528&date=2003-09-29
Hooligans, lots of them. Not just football hooligans, a lot of thug-like characters in general who will surely come out to play.
The biggest competition to Greece and Italy for Euro 2012 comes from Poland/Ukraine for the reasons I mentioned in a 'Euro 2012 hosting bids' posting. In addition these are some of the stadia that would host the tournament and they are already under construction. Shakhtar Stadium - Ukraine http://www.stadiumguide.com/shakhtarnew.htm Stadion Lecha - Poland http://www.stadiumguide.com/lecha.htm Stadion Wisly - Poland http://www.stadiumguide.com/wisla.htm However I still believe Greece is better equiped to host the event simply becuase they already have built 6 stadia that were used in the Athens 2004 Olympics and are about to build another 3. The Athens Olympic Stadium ( Where the opening and closing games would be held ) http://www.stadia.gr/oaka/oaka-f.html Karaiskaki Stadium ( Olympiakos FC Home Ground ) http://www.stadia.gr/karaiskaki/karaiskaki.html Pancretan Stadium in Heraklion Crete http://www.stadia.gr/pankritio/pankritio.html Panpeloponesian Stadium in Patras http://www.stadia.gr/patras/patras.html Panthessaliko Stadium http://www.stadia.gr/panthessaliko/panthessaliko.html Kaftanzoglio Stadium ( Iraklis FC Home Ground ) http://www.stadia.gr/kaftanzoglio/kaftanzoglio.html Thew new Panathinaikos Stadium - ( Not built yet ) http://www.stadiumguide.com/paoathensarena.htm The new AEK Athens Stadium - ( Not built yet ) http://www.stadiumguide.com/aeknew.htm