The German Constitutional Court has just confirmed the constitutionality of the Lisbon Treaty. You can find the details in the English press release and in the preliminary English version published by the Federal Constitutional Court.
However, it demands the re-formulation of an accompanying law (with non-constitutional character) that guarantees the influence of the German legislative branch (Bundestag and Bundesrat).
As long as this law is not re-formulated, the Lisbon Treaty may not be ratified.
The will of the people expressed by elections has to be guaranteed in practice, says the German Constitutional Court. It must be secured that the EU does not get the right to obtain competencies on its own but only by a democratic decision of the democratically elected bodies.
The German constitution in its present form would not allow Germany to be part of a European Federal State, so EU competencies may only come from the clear will of the people as expressed by the legislators.
This decision is a clear strengthening of the democracy principle in the context of EU-lawmaking, while leaving enough room to design the respective law on the concrete involvement of the German legislative branch in EU-related decision making without rejecting the Lisbon Treaty as such.
In my point of view, this is an excellent and extremely intelligent judgement, because it clarifies something that is extremely important: It is not just a question of how European Treaties are designed how much influence elected national bodies have but a matter of the concrete design of influence structures on the national level.
It is easy to blame the EU for a lack of democracy, but seeing the influence (and intransparency) of the executive branch in EU decision-making, a good deal of the undemocratic character of EU-decisions is the result of a missing ability of the parliament(s) to control their governments when they decide on the EU-level.
By demanding to guarantee that national (!) procedures have to be democratic when it comes to EU-lawmaking, the Court has underlined this important point. This judgement is thus pro-EU and pro-democracy - and that is extremely positive!
The question will now be, how quick the German legislator will be able to formulate the respective law - especially since the political parties are already entering into the election campaign for the Bundestag elections at the end of September...
See also: The German full text of the judgement.
Update: According to German news sources, the Bundestag will hold a special meeting on 26 August to deal with this issue. According to tomorrows FAZ, the second and third reading shall take place on 8 September so that the the Bundesrat - the second chamber - could agree on 18 September. Afterwards, the German president could ratify the Lisbon Treaty.