Nice editor. Though I wonder with all the font links lately, is the world really short on fonts? Shouldn't Google fonts and the like just about cover any need?
Google fonts is incredibly frustrating as soon as you look beyond skin-depth. For one, it's annoying to use Google Fonts for professional work, because more often than not the font you want to use is available in only one weight, or it's missing an italic style, etc. So, you walk in thinking you're going to come out with a terrific type solution for your client or project, and you walk out realizing you are effectively being upsold by a type designer. Not that it's a terrible thing.
Now, let's say you look at the full catalog of commercial fonts. What's happening is a sort of acceleration of fashion. No sooner did the squared serif font come into style than it is on its way out. People are designing new fonts, other people are enjoying the new stuff, and the old stuff gets pushed out (not completely, ever, but enough that your average designer starts to really get annoyed seeing the same old fonts).
So this tool is probably a great thing--it should help boost the industry and it will also put more downforce on the value of the same old junk that has been around forever. So if you are really OK with standard fonts, or plan to use free fonts forever, there should be an increase in the amount of that stuff that is available for you to use.
This should also help commercial fonts take hold. People will start to notice fonts more, and they will start to understand the difference between the amount of work that goes into paid fonts vs. unpaid.
Google Fonts has only single style families on purpose, to prioritize a limited budget, so the most popular single style fonts can be improved into families with confidence there is demand for them.
But expanding single styles into families is not as easy as it should be. That's why I help start http://metapolator.com which takes www.metaflop.com and removes the 'write metafont code' part of the process.
As you say, if you want the fonts to be better sooner than Google, you can pay for it - either by commissioning the designer to improve the open source fonts or by going across the street to a paid web font service.
