I would hate to lose them too, after all what would you replace them with? We have five different William W. Johnstone series coming out, Soon Deathlands and Outlanders will be caught up and down to 4 a year as they get published, the Deathstalkers will be done, the Doomsday Warrior and Survivalist will probably only be out one more year or so (both series have a limitted number of books). GA needs to keep a well rounded variety of titles. And with the huge popularity of the Executioner comic I would think that they would be foolish to completely get rid of the Mack Bolan series. I could see them go quaterly maybe.
It seems to me however, that Stony Man is consistenly the most popular of the Bolan universe (although I might be biased in this) I think that should go back to monthly. Especially with some of the terrific new ones out now--Splintering Sky totally rocked.
But this is just my idea.