According to ITworld Daily, Adobe is gearing up to sue Apple over the new restrictions on cross-compilers in the latest version of the iPhone Developer Agreement. (Standard disclaimer here: I'm not a lawyer, this isn't legal advice, and your mileage may vary.) What I'm not sure about are the grounds under which Adobe will sue.
Apple isn't a monopoly; the iPhone isn't the most popular smartphone (RIM's BlackBerrys still hold that distinction.) The iPad just started shipping, and companies have built tablets for years. A company can't be a monopoly in its own products, and Apple has the right to put whatever restrictions it wants into its own agreements, so long as those restrictions aren't illegal. It doesn't appear that Apple induced Adobe to implement its Flash-to-iPhone cross-compiler; Adobe made that decision by itself, to get around Apple's previous restrictions on Flash. Apple had no legal obligation to inform Adobe of its decision to ban cross-compilers before it made the announcement. No developer is forced to sign Apple's new agreement unless they want early access to the iPhone 4.0 SDK.
So, I'm not sure what grounds Adobe is going to use to sue Apple, if it files suit at all. After all, for several years, Adobe either refused to release applications for OS X or released them later on the Mac platform than on Windows. Premiere Pro was unavailable for the Mac for several years. Adobe's actions definitely hurt Apple, but Apple never filed suit against Adobe to force the company to port its applications to OS X in a timely manner.
This may all be a PR scheme on Adobe's part to try to get Apple to change its policies. It doesn't seem as though Adobe has very strong grounds for a lawsuit.