Air Guadeloupe is no more - sort of.
What has happened is that several French West Indies airlines - Air Guadeloupe, Air Martinique, Air St. Barth, and Air Caraibes - have combined and now operate under the Air Caraibes banner. In theory, this streamlines their operations and provides a full-fledged regional airline.
Most of the planes still have their old paint jobs, and my travel agent told me last month that computers still show flights under the old names (even though the merger was announced in July).
I don't think you should be particularly worried, but after flying the individual units a number of times over the years, I wouldn't exactly call them an all-pro outfit either. Your options to Martinique, however, are limited (Air France from Miami, LIAT from neighboring islands). The Air Caraibes personnel at the St. Martin airport are awful.
Bon voyage!