Apple today issued a notice to European distributors indicating that it will halt sales of the Mac Pro in Europe and select other countries as of March 1 due to new regulatory requirements going into effect on that date

From MacRumors:

The move will affect all European Union countries, as well as EU candidate countries and the four European Free Trade Association countries: Iceland, Liechtenstein, Norway, and Switzerland. As of March 1, 2013, Apple will no longer sell Mac Pro in EU, EU candidate and EFTA countries because these systems are not compliant with Amendment 1 of regulation IEC 60950-1, Second Edition which becomes effective on this date.

 Apple to Halt Mac Pro Sales in Europe Effective March 1 Over Regulatory Requirements