As if Apple didn’t have enough going on with Saturday’s iPad launch, the company yesterday sent invitations to journalists for an event that promises a “sneak peek” at the forthcoming iPhone OS 4. The event is scheduled for this Thursday in San Francisco. Tops on Apple enthusiasts’ wish list are the ability to run more applications at the same time and support for Adobe Flash, although Apple has given no indication it will add Flash.

An upgrade to Apple’s iPhone OS has a large order to fill. Consumers, as well as those in the gadget community, have been calling for a host of improvements to the iPhone, as platforms like Android continue to add new features to their SDK.

A spring preview event is quickly becoming an Apple ritual. In March of 2008, Apple took the wraps off its iPhone SDK, and just last March, the company unveiled the iPhone OS 3.0. Actual launch of the software has run concurrent with Apple’s June or July release of new iPhone models.