Just in case anyone was wondering, that 54g SMC router (SMC2804WBR) that Best Buy has been offering such a good deal on over the last couple of weeks ($80 after discounts and rebates) works perfectly with OS X.
I picked it up and have been using it with my iMac (via E-net to one of the 4 ports in the hub) and my Ti book (using a LinkSys 54g PMCIA card). Like other similar products you can configure the network using your browser.
Tried it out yesterday with a Rogers connection (after configuring it at home with no high speed access) and it was basically plug and play.
I'm getting the Sympatico kit later in the week so I'll post back with that experience but I don't anticipate that there will be any problem with PPoE either.
Link to product page.