First the acronyms:

FISA = Foreign Intelligence Surveillance Act
NISC = Foreign Intelligence Surveillance Court - special Federal District Court entrusted with FISA matters
NISCR = Foreign Intelligence Surveillance Court of Review - special Federal Court of Appeals which reviews NISC decisions

The case is titled “No. 08-01, In re: Directives (redacted text) pursuant to Section 105B of the Foreign Intelligence Surveillance Act.” The public opinion is also redacted in places.

SCOTUSblog analysis is here.

Intelligence wiretap power upheld
Thursday, January 15th, 2009 9:38 pm | Lyle Denniston
....
In a case that potentially could go to the Supreme Court, a special federal appeals court that operates almost entirely in secret has ruled that Congress did not act unconstitutionally in giving the government power to order telecommunications companies to aid in warrant-less national security wiretapping — eavesdropping mainly aimed overseas, but possibly reaching inside the U.S. and American citizens.
....
The impact of the ruling on the legality of the National Security Agency’s highly controversial electronic eavesdropping operation was not very clear Thursday, since the specific federal law at issue has expired, the ruling was limited to the specific facts of the case, it technically applies only to cooperation directives and thus does not resolve any issues of privacy of those who are overheard on the taps, and the Court of Review went to some lengths to suggest it was ruling as narrowly as possible. Even so, the decision sought to remove any significant constitutional doubt about the intelligence-gathering that has gone on since at least late 2007. (While the specific law at issue has expired, a replacement law has authorized continuation of the government’s eavesdropping power.)
The 29 page opinion is here.

This opinion is more interesting (and important) in its method of deciding what issues were material and how those issues would be approached.

First off, the court did not take on FISA's constitutionality using a broad brush approach - The "Isn't this a terrible statute" argument was not considered. Rather, the court looked at whether the law, as it has been applied based on the facts before the court, is constitutional in that aspect - and in that aspect only. Thus, the opinion is filled with caveats - i.e., we see that this or that might be a problem, but we are not going to decide that problem until it actually arises.

Thus, this opinion cannot be read as a series of blank checks which NSA can cash at will; nor, is it what many have wanted to hear - unconstitutionality.

Whether this decision will go up to SCOTUS is presently unknown. What the Obama administration will do in this area is also unknown.