Wow!
When I posted the question I got 1 reply and thought oh well it must be a bone question never mind. Then I have another look and now I have this lot must be from over the pond me thinks

All of you thank you for the fantastic response I now understand it all a lot better.
The reason for the question was I have 400d, 40d, and the 7d along with
Canon FD 50mm F1.8+FD to ES conv = 1.4
Sigma 10-20mm f/4-5.6 EX DC HSM
Canon EF-S15-85mm f/3.5-5.6 IS USM
Sigma 17-70mm F2.8-4.5 DC Macro
Sigma 18-200mm F3.5-6.3 DC OS
Canon EF-S 18-55mm f/3.5-5.6
Canon EF 28-135mm f/3.5-5.6 IS USM
Sigma 30mm f/1.4 EX DC HSM
Canon EF 50mm f/1.8 II
Canon EF-S 60mm f/2.8 Macro USM
Canon EF 70-300mm f/4-5.6 IS USM
Canon EF 70-200mm f4 L IS II USM
Sigma 150-500mm f5.0-6.3 DG OS HSM
2x EX DG Tele Converter on 70-200 Canon
2x EX DG Tele Converter on 150-500 Sigma
And was wondering if I should get rid of the EF-S and the 3 body's if the new 7D was full frame or do I keep them in case something was invented that could use both but now I understand that the most economical way forward would be to get rid of them
Thanks again for all the VERY informative reply's
I have been on a lot of forums and there is not one bad post in this lot normally on a forum you get at least one dick head who cant resist a p**s take
Thanks.
Great web site as well Craig