We cannot give up on another young pitcher in my mind. The backlash would be too great if KW traded Jon, and he really came on next season.
Look at Jake Peavy's season last year compared to this year's.
2003 - 12-11, 156 K's, 82 BB's, 4.11 ERA.
2004 - 14-6, 162 K's, 52 BB's, 2.25 ERA.
Also look at Oliver Perez's numbers.
2003 - 4-7, 5.38 ERA with San Diego. 0-3, 5.87 ERA with Pittsburgh.
2004 - 10-10, 3.14 ERA, 225 K's, 75 BB's.
Jon would be a perfect 5th starter for us next season, and there wouldn't be as much pressure on him to perform, if we signed a top of the line starter.