How about:
hasSiblings
or isFollowedBySiblings (or isFolloedByItems, or isFollowedByOtherItems etc.)
or moreItems
Although I think that even though you shouldn't make a habit of braking 'the rules' sometimes the best way to accomplish something may be to make an exception of the rule (Code Complete guidelines), and in your case, name the variable isNotLast
