Flybe share price up by 15% today - so the market seems to view the possible sale of some or all of the LGW slots as positive. Note that Flybe have said some OR all.
As has been mentioned previously, should Flybe withdraw from the IOM - LGW service, the IOM Government's Open Skies Policy will have failed in its attempt to promote a 'frequent and reliable' air service. The IOM passenger market is finite, and there will not be enough business to support more than two 158 seat A319 LGW rotations per day. A 50 % reduction in the previous frequency.