Well I'm no economist, but that doesn't surprise me.
The Euro is stable (strong against your dollar) and has done remarkably well for such a young currency.
Member states experienced variable levels of growth last year (where I live, France, 2.4%). Of course problems exist, notably unemployment (around 10% in France and Spain, but extremely low in some member states such as the UK).
I generally have a problem with statistics and standard econommic measures, since they tell us very little about the life of the people as it's actually lived. For example, the USA is theortically the worlds largest economy by various measures, but what does that actually mean to the unemployed black in south central LA with no health insurance? Very little. What I would say about the EU is that we enjoy a good standard of living, more evenly spread across the population, with less of the extremes of obscene wealth and real poverty that you have in the USA. Food, accomodation and the basics of life are affordable, with good safety nets for the poorest. Taxation is high in many member states, but most realise the necessity of this to fund our generous health and social programmes (community before individual - a major difference to US society). Education and health care for all are taken for granted as basic rights. The mood is generally optimistic, and the absoption of our new member states hasn't caused the end of the world as some sceptics predicted. Those of us in the richer nations are prepared to scarifice a little to help our poorer neighbours reach our level of development (as happened with Ireland, Spain and Portugal) - which is one of the great things to me about the European ideal, which I believe will promote peace and security in the region, and mutual economic benefit in the long term.
Of course it's not all rosy in the garden. Disagreements in the new constitiution need to be ironed out before ratification, and that may not be an easy ride, but we'll get there just as we did with the Maastricht and Nice treaties. Persuading the UK to join the eurozone when their own currency and economy are so strong will be another hard battle, but I believe we'll get there. In short, I believe the EU will be a strong economic force, strong enough to deal with the challenges we'll face by the growing Asian economies of India, and notably China, who are undoubtedly going to lead the world economically. I believe we'll be far better placed to compete with these new forces than the USA, which frankly, has had its day.