If you're using Twitter, you can follow people who often post about Miva Merchant, including the company itself! I've compiled a list of Tweeple who are in some way related to Miva Merchant - developers, designers, hosts, users, etc. and put them in a Twitter List:
Bookmark the list because I'm going to add to it as I find new Miva-Tweeple. If you are not on the list, let me know at @MerchantTuts and I'll add you.
Thank you to Sabine Sharp (@GlendaleDesigns) for help in compiling this list.