Google expanded the Google Gadget directory with a new function which makes it possible to use the listed gadgets or modules directly on your website.
This feature was already available for websites created with the Google Page Creator and is a useful feature for webmaster with limited coding skills. The only thing that webmasters need to do is to add some html code (IFRAME) to the web page. The Google Gadget control makes it possible to add some fancy frames to each gadget.

Exactly as you say, I expect mostly starting webmasters to use it. I for one would always go for a custom solution, not even speaking about the thought of Google “overtaking my site” that worries me.
I think it’s also a way to get new traffic, new webmasters getting a way to add features like a whois query to their site without a lot of html knowledge.
Well it appears that Google is trying more and more to dominate the world.
Anyway, my opinion is that this is usefull only for newbies, as real developers know that they need a unique site, and this can happen only when you write your own code