IMO the EU is (and has been for many decades) like a road that is always under construction or maintenance hence problematic for its users (ie citizens), thus this irritating approach to EU construction has to be abandoned and the final design has to be shown to people and voted upon, no fuzz, clear!
If the wise men of Europe design an EU that works for the average person and the small company, then that will be a really deep + real "EU"
Key design criteria: a single EU "space" for small companies and average people to live, work, do business, with simple and EU-wide laws only.
In other words, a real European "Common Market" that works for small companies and real - average people is a much deeper EU than the one we have now or will have as the Lisbon EU Treaty goes into force.
PS. IMO the USA is not a good model for deeper EU. The design must be simpler, less bureaucratic + with direct access of EU institutions to the people and vice-versa.