Google Yanks Yet Another Useful Feature with No Warning: Labs "Add any gadget by URL"

Boo Google, boo.

Well, if anyone needed another example of why it's just a bad idea to rely on Google APIs for anything important, here's another one. Today I saw a teensy note appear at the top of my gmail announcing the Labs "Add any gadget by URL" gadget is being deprecated.

I used this feature to developer my "Hashcash mint" gadget, and it's the easiest way to add such gadgets to the sidebar in one's gmail.

I've sent them feedback asking what migration strategy one should use and how exactly someone is supposed to embed gadgets in their gmail page now.. I hopefully will hear back within the next few days.

Perhaps I need to look further into the OAuth2 system or something; but I fear the response will be something like "Port it to a Chrome extension" (which I've already done, but that's not cross-browser is it?).
Anyone else know of APIs which allow embedding of one's custom gadgets into pages like GMail, Calendar etc. without using some kind of Google walled-garden to host them?

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EDIT: No response yet.. the entire Google Developers section on gadgets is woefully out-of-date. I submitted about 4 support requests relating to dead links, missing sections, and just plain wrong info. Sigh. I get the feeling the entire gadget API has been left out to die, at least for people outside of Google.

Well if so, I'm glad I've only written one Google gadget and chrome extension, rather than investing more effort. Google just drives away devs by constantly deprecating things willy-nilly.