Yes it is good Abu is being deported there as dangerous terrorists are better off being prosecuted in a country with very harsh sentences and prison conditions like the U.S. Anyone who seeks to(or anyone who preaches hatred causing people to) blow up, kill and mame general public in their day to day activities cannot be punished harshly enough in a soft touch of a country like the U.K.
Don't completely agree with the U.S system, it has its pros and cons as with any system.
The scary thing is the ease with which the U.S may eventually be able to get people deported to there from here in the U.K. Mind you, if there is little media attention on whoever they are after they can just abduct anyone and take them if they want them bad enough as we have a few U.S bases over here.
However the thought of the innocent people who may slip through the net and get deported and found guilty of something over there is very saddening.