UPDATED:
According to an entry on Amazon, there is in fact another volume of Littlest Pet Shop; scheduled to be released June 4, 2013.
Littlest Pet Shop - Sweetest Pets
According to the write-up information, it's priced the same (more or less) as the previous volume, which is yay! And the run time is 110 min. So I would assume we could rest easy with this one being another budget priced DVD, and with another five episodes of content.
I can only pray that they continue releasing the episodes in chronological order.
