The "b" in "1.0b" suggests beta, so that may give credence to your impression it's "sloppy." Or it may just be the successive release after 1.0a. However, as you say this bot is not new, and I'm pretty sure I've been seeing some version of it for a decade. What I'm seeing at my sites is:
keyplyr: I get the beta indicia, of course. But all-lowercase msnbot-media's at least up to 1.1, even though it's been around for years and years; and this was not the also long-seen "msnbot/2.0b" variation. Plus I've never, ever seen included-and-escaped quotes with any MS bot. Those are Coding 101 bloopers.
lucy: The referrer -- atypical to see one at all with msnbot -- was a legit link, albeit a very old and rarely seen one. The one hit (which was 403'd) was to favicon.ico, not precisely the "images and video" claimed by MSN. [bing.com...]