I decided to "get out of" .40 a few years ago... I had a few pistols in .40, but decided to keep one just in case I ran out of 9 and 45 and could only find 40. Caliber consolidation is good, but I like the flexibility of caliber diversity.
My personal thoughts is to get calibers that use as common of reloading components as possible. But then, I'm a commie gun lover too. (easy to keep similar parts when they all run on 7.62 ) Honestly though, if you don't shoot it, sell it to someone who will, and get something you like better, otherwise ammo storage gets to be a bitch. (at least it does for me, but then again, commie spam cans of 7.62x54r and x39 are comparatively cheap and i just can't resist them.)