mixed bag

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun A collection of dissimilar things; an assortment.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun any bag containing a mixture of something
• noun by extension, a group of entities with few characteristics in common; an assortment
• noun idiomatic something tending to have both good and bad results or characteristics; something having a mixture of advantages and disadvantages

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun a collection containing a variety of sorts of things