I think that they should do something similar for URL's as they have done for trademarks, except they should make it for 6 months to a year:
The rights to a trademark can be lost through abandonment, improper licensing or assignment, or genericity. A trademark is abandoned when its use is discontinued with an intent not to resume its use. Such intent can be inferred from the circumstances. Moreover, non-use for three consecutive years is prima facie evidence of abandonment. The basic idea is that trademark law only protects marks that are being used, and parties are not entitled to warehouse potentially useful marks. So, for example, a recent case held that the Los Angeles Dodgers had abandoned rights to the Brooklyn Dodgers trademark Major League Baseball Properties, Inc. v. Sed Non Olet Denarius, Ltd., 817 F. Supp. 1103 (S.D.N.Y. 1993).
I hate it when I'm looking for a new URL and find that most of the ones I want have been taken and not being used, sometimes several years after they were originally registered. It just does not seem fair.
Lester