Lastly, the social and political issues surrounding the first major sporting event to be staged in former communist countries since the 1980 Moscow Olympics, could still endanger the tournament's overall success.Spain at ease with favourite status
There have already been diplomatic ructions between Ukraine and some western European nations threatening to boycott the event at government level over the jailing of former Ukraine Prime Minister Yulia Tymoshenko.
On Tuesday, three days before the tournament starts, a crowd of Ukrainians, angry over a parliamentary vote that would increase the role of the Russian language in the country, clashed with police at a fan zone set up in the capital Kiev.RACIAL ABUSE
Fans in Poland and Ukraine already have a reputation for racially abusing black players who will feature in matches from Gdansk in the north of Poland to Donetsk in eastern Ukraine.
Italy striker Mario Balotelli said last week he will walk off the pitch if he is abused, and European soccer's governing body UEFA will be expected to offer total support for the players and team officials in the event of any trouble.
Nothing would be more damaging to the reputation of the host nations if a match is abandoned in front of a global TV audience of millions because players have walked off after suffering racist abuse like that featured in a BBC documentary last week.
Away from the politics and off-field concerns, the finals are full of potentially outstanding matches.
England's Frank Lampard, who will miss the tournament through injury, and fellow midfielder Wesley Sneijder, who was part of the Netherlands team beaten by Spain in the World Cup final two years ago, agreed that the Euros were harder to win than the World Cup and were also of a higher standard.
"It will be very difficult because, for me, the Euros is more difficult than the World Cup because you don't have the teams from Africa or wherever when you know you are going to take three points," Sneijder said.OPEN TOURNAMENT
Current form would bear that out with 13 of FIFA's top 20 ranked teams in the finals, including Spain, Germany, France and the Netherlands who all look as if they could win the final at the Olympic Stadium in Kiev on July 1.
Italy may be engulfed in a new match-fixing scandal but their national team can also never be discounted when major tournaments come around.
But as Denmark proved in 1992 when they were champions after coming in as a late replacement for banned Yugoslavia, and as Greece also showed in 2004 - winning the tournament after starting as 100-1 outsiders - no team can be entirely discarded.
Spain, with the backbone of their Euro 2008 winning side still in place, meet Italy in an intriguing opening Group C game in Gdansk on Sunday. If they win they should have no trouble qualifying from a group that includes Croatia and Ireland.Fabregas scan shows positive results, Spain say
Germany, who won the last of their three European crowns 16 years ago, were impressive in the qualifiers, winning 10 straight matches, and on current form should advance from Group B with the Dutch ahead of Portugal and Denmark.
Co-hosts Poland, who at 65 in the FIFA rankings are the lowest ranked in the tournament, will rely on a trio of Borussia Dortmund players, including striker Robert Lewandowski.
The will seek to win a match at the European Championship finals for the first time and advance from a group that includes Russia, Greece and the Czech Republic.
They get the ball rolling with the opening game against Greece in Group A at the National stadium in Warsaw on Friday.
Ukraine will, like their co-hosts, be spurred on by a passionate crowd against England, Sweden and France in Group D.
The French, European champions in 1984 and 2000, head into the finals on the back of a 21-match unbeaten run and look likely to advance from the group though who will join them is anyone's guess.