In a bee-related nutshell - need we worry about horizontal transfer of GM genes to bee gut bacteria?  GM companies no longer use antibiotic resistance as a marker gene (ah, but why?), so it is unlikely that *new* crops will transfer antibiotic resistance to bee gut bacteria.

For humans, if we are concerned we need to get informed.  If we are informed and are still concerned we need to make noise that someone who can respond will listen to.  On a personal note, I am concerned about the potential side-effects of covering huge acreages of land with genetically modified crops whose behaviour is not entirely predictable.  Just by chance, something will happen.  What - like horizontal transfer of an herbicide resistance gene to a weed, or BT (an entomotoxin) to wildflowers - no one can predict.  For the record I am a molecular entomologist by profession and I am not doing GM work.  My statement may be considered biased because my personal, which I consider informed, view is that GM products are unnecessary to ensure human well-being, "food for the starving"  or effective farming.

Martin Damus