Per Keith Weiland's Salary Cap page
and some guestimation on my part here are the following cap situations of Weaver and Greenwood:
Weaver will cost us 6.2m if he is on the roster this year. If we cut him we would be on the hook for 8.1m (2.7m bonus allocation per year) as he is sigend through 2010. Therefore, before any fuzzy accounting, it would cost us 1.9m (8.1m minus 6.2m) to release him and have a roster spot. He is as good as gone, if there is someone who has looked better in camp. Since I have not been at camp I certainly cannot provide a valued opinion. All I know is that he is extremely expensive for the "value" he provides on the field.
Greenwood will cost us 4.017m if he is on the roster this year. He is signed through 2009 and his bonus allocation is 2.9m for the two years. Therefore, 4.017m minus 2.9m means we have immediate cap relief to the tune of ~1.1m by cutting him.
Therefore, if we cut them both it will cost us 800k this year on the surface. This is not a failsafe look as there are determiners, formulas and variables that must be considered, but on the surface an 800k pricetag on a 109m Cap is peanuts to get rid of these two players and get some playing time for some younger folk.