[capableweb]

Sounds like a great idea for translators who are also programmers, or at least knows HTML (and syntax for logic, judging by your examples). But I haven't worked in any companies where the translators/the people doing localization have been programmers, they have just been translators. This will be more or less impossible for them to use efficiently, if at all.

[LeviticusMB]

Well, you have to start somewhere. Anyone can learn how to call a function, just like they can learn MessageFormat. And basic HTML is something translators must already know.