The HTML of a Squid-cached anonymous page view contains:
<link rel="stylesheet" href="http://bits.wikimedia.org/wikimediafoundation.org/load.php?debug=false&amp;lang=en&amp;modules=site&amp;only=styles&amp;skin=vector&amp;version=20101228T232335Z" type="text/css" media="all" />

and

<script src="http://bits.wikimedia.org/wikimediafoundation.org/load.php?debug=false&amp;lang=en&amp;modules=site&amp;only=scripts&amp;skin=vector&amp;version=20101228T232335Z" type="text/javascript"></script>

which means changes to site JS do not propagate well for anonymous users. Because Varnish caching is aggressive, a hard refresh doesn't help.

Trevor, shall we talk about how to handle this on Monday?

Version: unspecified
Severity: enhancement