This move makes sense in every sense for me, more depth, more steel in midfield, more options, and a good deal for Everton who can then splash out a bit. The only thing would be I'm not that keen to lose Welbeck, think he is far too talented. I can see him becoming a real star this year as our third choice striker, as Berba and Owen slip down the pecking order.
In sum, Gibson + cash for Rodwell would be excellent in my eyes, and be a good way to finish up the summer spending.