Once apps get optimized for the 6+ and developers take advantage of the screen real estate you'll be wishing you kept them. Until then, enjoy your 6.
Will they though? Sure, some larger developers (Facebook, Twitter, ESPN, etc) might make iPhone 6 Plus optimized versions of their apps, but will it be a worthwhile use of time and resources for many smaller devs to do the same? How about those that have iPhone and iPad specific apps? Now they are going to make a third?
I'm sure a few will, but I can't imagine its going to be a huge rush to make that happen. At least not in the short term.