Over the next few weeks, we’re going to get our first inkling of whether all of this talk of open networks is real or just a bunch of hogwash. On Thursday, Apple will give the world its first peek at the iPhone software developer’s kit (SDK). And on May 19, Verizon Wireless will release its own open-network developer’s kit — not so much an SDK as a set of specifications that would allow third-party device makers and app developers to shoehorn their wares onto VZW’s network.

Both events could have enormous implications for the wireless industry or they could be big let downs, depending on whether either company lives up to its own hype. The Apple SDK could open up one of the most innovative and powerful wireless devices to thousands of new applications and uses, or it could just be a way for Apple to allow a few friendly developers access to its APIs. The same goes for Verizon. If it really does reveal an open set of APIs to the Verizon 3G network, it will could set the stage for a revolution in wireless gadgetry on one of the world’s most powerful broadband networks, but it also could make those specs very stringent, severely limiting what devices finally make the cut.

Unlike the typical standards process, where dozens or hundreds of companies form slow-moving hulking committees that set rules for interoperability and access, Verizon Wireless and Apple are acting as the sole policeman guarding access to the network or handset. That allows them to be extremely quick, but it also permits them to be ruthless if they so choose. Neither company has much of an interest to restrict all access (The are taking the very encouraging step of releasing developer kits after all), but it’s probably not in either company’s best interest to do away with a bouncer and cover entirely.

In any case, Verizon’s conference is still two weeks away, so let’s take a closer look at Apple’s conference tomorrow.

One of the key elements of the Apple event in Cupertino is expected to be the first third-party enterprise software for the phone. A few companies have managed to link the corporate e-mail servers to the iPhone, but it’s hardly out-of-the-box ready for the executive crowd like the BlackBerry. As BusinessWeek points out Apple CEO Steve Jobs wants the iPhone to be more than just a neat gadget for connected hipsters, but in order to do make inroads with corporate, Apple needs to let Microsoft’s Outlook and IBM’s Lotus onto the device. That means a development platform that will support something besides Apple-sanctioned apps. Ostensibly that’s what we’ll get the first glimpse of tomorrow.

But reports are already emerging that the Apple SDK won’t be quite as open as promised. iLounge reported that Apple plans to act as a gatekeeper for all applications, basically turning the SDK from a developer’s kit into an approved partner kit. FierceDeveloper writes that such a policy would clearly favor huge developers who would have their applications moved up the priority and, if true, could reflect either Apple’s intention to take a revenue share from every iPhone app sold or Apple’s desire to keep the still pristine iPhone free from complex or crappy applications. Either way, Apple would ultimately maintain control.

Of course, this is all speculation until Jobs unveils the goods on Thursday, but Apple does have a history of keeping a tight grip on its products. The iPhone in particular has attracted just as much attention for the things it won’t do as it has for the truly astounding things it will do. Jobs has a justification for why the iPhone didn’t launch with 3G connectivity, why Apple couldn’t support the phone over multiple operators in a single market, why application development was originally restricted to the Safari browser.

Take the latest dust-up between Apple and Adobe: Jobs told investors today that the reason iPhone doesn’t support Flash video is because Adobe’s FlashLite platform for mobile phones isn’t good enough. Call me cynical, but I would not be at surprised if that same “can’t” refrain doesn’t continue sounding at tomorrow’s conference. But then again Apple could surprise us.