The fifth Snow Miku will be released early next year, and a competition is being held for anyone to submit a design for consideration. The theme for this fifth design (though, strictly speaking, only the fourth anniversary from its beginnings) is 'Magical Girl Miku' and must include some kind of magic wand and what is termed a pet. That useful site piapro has the details, though only in Japanese.
The contest was launched just over a week ago, and already there are around fifty designs submitted to the site, though there doesn't seem to be a specific web page for this to which I can provide a link. Take an example page, though, and look toward the foot of that page where several of the others are shown. Following these tends to bring more of them into the frame (and other images as well, so one needs to pay attention to what is being offered), so it is possible to check them all out via this somewhat circuitous route.
Some of the submissions are great, others are good, and a few are not so good. The standard of artistry is mixed though generally high, and it's all looking good. It's definitely compelling to fans of Miku (especially to those who like the Nendoroids) and/or cuteness, though not really worth making any great effort otherwise.