> Is there an SEO benefit to having your pages not cached in the search
> engines? Any thoughts on this would be appreciated.
Are you thinking about something specific?
From the usability standpoint, having your page cached generally means faster access (and simply an access, if you website is temporarily -or permanently-, down), for advanced users... and if a user find what he wants, on your website, he might come back.
The majority of users, however, might not even know what it is about (well, some might have already heard people talking about it, on forums/blogs), and will generally not follow the "Cached" links.
For pure search engine optimization (better indexing), I don't think it is taken into account by any search engine... they will still index your website as regularly, and I don't think they would make websites "lose points", because they requested the engine, not to archive them... (well, I never read anything about it, anyway, and it would not make much sense).
This said, disabling archiving, means your website will not be indexed by archive websites, like archive.org, which might be yet another point of entry, to your website (and would permit users to see "how your website looked before", in a few years... -which adds a bit of community feeling).
Now, it depends what kind of website you are publishing...