The iPhone accessory market will likely get off to a slow start because of intense secrey by Apple regarding the connectors and features, according to a Reuters story.

iPod owners have been fond of adding various protective cases, FM tuners, and audio accessories to their music player. iPhone owners will probably be no different, but they’ll have to wait a little longer for the flood of gadgets and A/V accessories for the iPhone. The reason is that Apple’s secrecy surround thing the device has hampered pre-sales testing.

In addition, Apple has sought to maintaine a tighter grip on the compatibility of new accessories in order to ensure a successful launch, according to Jeremy Horwitz, editor-in-chief of iLounge.

However, with little information available prior to June 29th, accessory manufacturers like Belkin and Griffin have been limited to the most basic items, basically protective cases and charging cables.

One issue is that some iPod audio accessories, designed simply to listen to music, won’t work well with the iPhone which requires an integrated microphone with the earbuds or a headset.

In fact, the iPhone will open new opportunities over and above the iPod, such as keyboards and wireless headsets. "There’s a lot left to be defined. With the iPhone, all of a sudden there’s the Web aspect, camera, e-mail and a whole lot more. It really opens the door to what’s available," said Alex Birch, iPhone category manager for Griffin Technology.

Currently, consumers spend about US$1B each year on iPod accessories and whether the iPhone cannibalizes that or expands the market is not yet clear.

In time, this will all get sorted out. New iPhone buyers will be so engaged with their new hand-held computer and mobile phone, they may not notice the delays. Those who are anxious for such add-on toys, however, will just have to wait a little longer.