The import of the use of reference works in court cases is frequently misunderstood, and in this case Wikipedia is no different. Wikipedia has been used as a source across culture (e.g., in cartoons, on TV), by governments -- for different reasons -- and a lot of attention is given to examples of Wikipedia as a court source. Seemingly, if a court cites a reference work it connotes authority and legitimacy upon the source. However, the legal meaning is quite different: the principle of judicial notice applies to information introduced into the court record that is so commonplace that it cannot be refuted. It is not a case of authoritative or expert evidence being recognized, as it is often misunderstood to be, but closer to a recognition of popular notability.
Britannica was quite famous for its misleading and sentimental advertisements in the 1950s and 60s including an exaggerated claim about the courts, as Harvey Einbinder discusses:
The educational director of the Britannica supplied a good illustration of these dubious claims when he asserted in an advertisement in the Library Journal (November 1, 1954): "It is so universally accepted as an authority that courts of law admits ENCYCLOPAEDIA BRITANNICA as evidence."... However, it is an elementary legal principle that judicial notice can only be taken of scientific facts or matters that are generally or universally known, and which therefore can be found and encyclopedias, dictionaries or other reference works. These facts must be matters of common knowledge -- and not questions where a difference of opinion exists. Thus the scientific treatise is and encyclopedias may be consulted by judges, but they are not evidence. One reason for this rule is that they cannot be placed under oath and cross-examined. Another is that citations in one book may be contradicted by other books unknown to the court. (Einbinder 1964:314-315)
So, first, Wikipedia is not the first reference work to be used, or misunderstood, in this way. Second, the interesting thing that is happening here is the degree to which a reference work's selections are an appropriate proxy for judicial notability, and a reliance upon Wikipedia perhaps indicates a more up to date, but also much more expansive, scope: print encyclopedias rarely ever exceeded a hundred thousand articles, the English Wikipedia has millions.