My gut tells me no-way! Cheechoo had one good season, getting 93 points in 82 games. Before that he had 47 in 81, and since the he had 69 (in 76 games) and 37 (in 69).
There are two trends there: missing more and more games, and getting fewer points per game. His career average is 0.7 ppg. Take away that 93 point season and it drops down to 0.578. Last year it was 0.536.
Vermette's career average is 0.468, playing on the third line and killing penalties. His production has also steadily increased, with 0.63 last year.
All the stats indicate that Vermette, playing solid 2nd line minutes (with PP time) will continue to improve, likely getting around 0.7 points per game or more. Cheechoo, on the other hand, is just as likely to get 0.6 or less, unless he has a nice rebound.
I'd rather keep Vermette.