It's been under the rumor banner for some time now, but we've been told by a trusted source that the long-awaited AT&T iPhone-as-modem tethering plans (preliminary details in MacBlogz' post from November: 5 GB data cap, $30/month supplementary cost) may be ready for prime time during Macworld Expo this week. The tethering announcement might not rise to a keynote-worthy level; it could simply be publicized as a press release during the show.
While $30 is a steep charge on top of an iPhone data plan, it's still cheaper than the $60 you'd pay for an EV-DO or HSDPA card plan for mobile data; for some users it may make more sense than a standalone device. Granted, you can already tether a jailbroken iPhone, but that may get you stomped on by the traffic cops rather promptly.
Another tidbit from our source lends credence to the MegiPod rumor (a larger form factor for an iPod touch device) floated by TechCrunch last week. No timeframes were discussed, so the late 2009 on-sale date is still in play. It's not clear how the hypothetical unit would achieve this feat, but the suggestion is that it would have "full application compatibility" with currently available iPod touch apps ... puzzling, as it implies either resolution-independence for the apps or some pretty impressive scaling tricks to accommodate the larger screen size.