Hi @Grant Palin:
I think the decision is your own. As said Automattic is merging its plugins into JetPack and encouraging users with older versions to upgrade. If you want to continue using those plugins you likely will not have a choice but to upgrade to JetPack with the alternate being to switch to other plugins.
I do expect the JetPack to be of high quality given the paid staff of Automattic maintains it. And as a counter to the “overkill” concerns I’d rather have fewer plugins listed in my plugin directory (fewer to update, fewer to have to understand, etc.) so I’d prefer to use JetPack instead of individual ones if I wanted to use more than one of the enclosed features because there is almost no overhead of significance to having the other functionality installed; certainly very little additional overhead on page load.
However, at the time I write this, you cannot use JetPack on localhost. This makes using it for a professional solution that requires development, testing staging and live servers for deployment not really an option (vs. just by a blogger for their own blog.) If they do not address this limitation (which they might) I expect we might see people forking the functionalities in JetPack.
In summary, Caveat emptor.