How hard do I rock?  Let me give you an example.

Date:  The near future.

Scene: David's blog, a jewel of php code, with a few custom modifications to the WordPress framework.  Does anybody else have an <image> element in their <channel> in their feed-rss.php family?  Doubtful.  Oh, how about user friendly "there's more content this way" ellipses in their wp_trim_excerpt() function in their formatting.php?  Ha!  The world would be so much nicer if only they did.

But what's this?  There's danger brewing.

A vulnerability in the pingomatic server unleashes a feedback ping ripping a hole via XSS into every single wp_footer().  Everybody who posts, pings.  And everybody who pings gets spam added to their footer.  And everybody who pings suffers a debit from their PayPal account.

Never fear!  Matt Mullenweg's team of crack coders patches the hole the exploit accessed in the WordPress code.  But now WordPress users across the world must scramble to follow the tedious upgrade instructions.  And then re-apply their custom changes.

Oh, the humanity!  Why isn't David panicking?  Why isn't he in despair?  Doesn't he realize the danger to his blog?!  Doesn't he realize the tedium that awaits him?

Let's zoom in and see what he's doing...

David grabs a few dark chocolate covered espresso beans, and casually pops them into his mouth.  He ssh logs into his blog's directory.  He types,

svn sw http://svn.automattic.com/wordpress/tags/2.3.2/

and logs out.  He's done.  His blog is updated, protected, and his customizations are intact.  He turns up his MP3 player and goes outside to enjoy the sun.

(In other words: My blog is now a subversion sandbox.  Whee!)