At first, this looks like a way for Google to drop all those useful plug-ins. You could look at it another way and say that it will help block malicious plug-ins.
Starting in January 2014, Chrome will block webpage-instantiated NPAPI plug-ins by default on the Stable channel. To avoid disruption to users, we will temporarily whitelist the most popular NPAPI plug-ins that are not already blocked for security reasons. These are:
Silverlight (launched by 15% of Chrome users last month)
Google Earth (9.1%)
Java (8.9%) *
Google Talk (8.7%)
Facebook Video (6.0%)
* Already blocked by default for security reasons.
In the short term, end users and enterprise administrators will be able to whitelist specific plug-ins. Eventually, however, NPAPI support will be completely removed from Chrome. We expect this to happen before the end of 2014, but the exact timing will depend on usage and user feedback. Note that the built-in Flash plug-in and PDF viewer will be unaffected because they donít use NPAPI. Google Says It Will Block Plug-Ins In Chrome From January 2014 [blog.chromium.org]
Software development gets a lot cheaper when you don't have to consider third parties.
However, from where I sit it seems as if Chrome has somehow gained a market share. The reason isn't obvious to me, but then I never invented the rubber band or safety pin either.
The chrome users seems to be to be somewhat/somehow in the "convenience" segment... exactly the types of users that would be incined to switch to another browser when something doesn't work.
So, disabling these things might be a little risky in terms of market share. But then, Google marketing might be able to turn the bright minds of these users into thinking that this browser-handicap is actually a benefit.
Its worth noting that 2 of the 6 listed are Google properties. They've been pushing Chrome pretty hard through TV ads of late, especially for phones and tablets. I'm guessing Google believes this move will not impact its market share, or that have something else in the works that they're not talking about yet.