The really funny thing, is that the phones are SLOW even when on AC power.

And it also affects some (all?) laptops as well, again on AC power, even with the old battery unplugged.

Weird.

The take-away I got from it is that, if one has a an Apple product that is feeling more sluggish than before, REPLACE THE BATTERY before thinking about an upgrade to the latest shiny toy!

Or at least follow the lead from that article and check the CPU clock speeds using the free (and almost free) tools linked in the article. This is a really easy issue to verify, regardless of the web site used to publicize it.