@prologic Yep, you can follow people on Mastodon via Micro.blog; you can actually follow any blog that’s on its own domain name, (including tumblr) via Micro.blog.
(FYI, any @-mentions that aren’t within a 280-character-limit post don’t become actual @-mentions. They have to be in a post that fits entirely within the 280-character limit.)
@smokey You need to clarify the "other blogs” bit on other domains. I would imagine (my Software Engineering in me here) that this is restricted to some subset of known protocols…? -- Also is the same true in reverse; Can Mastadon users follow me on my prologic.blog Micro.blog>
@prologic Second part first: yes, once you set up a Mastodon-compatible username as outlined in that Help article, Mastodon users can follow your www.prologic.blog posts in their Mastodon clients.
For the first part: essentially, any blog that is located at the root of a domain or subdomain (technically, has its RSS/Atom/JSON Feed feed referenced in the standard link discovery HTML by the page at the root of its domain/subdomain), can be followed on Micro.blog.
So blogs at example.com or blog.example.com work, but not ones at example.com/myfancyblog or example.com/~tildeusername, for example.
@prologic As long as it’s discoverable at the root of the domain—and probably the first feed, too; there’s no support for choosing, if different feeds are offered.
The support is like a limited-scope RSS/feed reader focused specifically on (personal) blogs, a middle ground between the community-style experience of Micro.blog and a full-fledged reader app.