Apple announced this morning that it’s long-awaited, thoroughly-dissected, hotly-contested iPad will be available for pre-orders in one week, with deliveries to begin April 3. The company will start with its WiFi models first, then add the 3G-capable units by the end of April.

Devices can be ordered online starting next week, or pre-ordered from Apple’s retail stores. Shipments start April 3 for online orders, with in-store pickups available the same day.

In a press release Apple’s Steve Jobs says the tablet, using a trademarked Multi-Touch interface, let users “connect with their apps and content in a more intimate, intuitive and fun way than ever before.”

The device that will deliver a renovated Mail program (included) and runs $9.95 apps for Apple’s Numbers spreadsheet and the Pages word processor, does not yet include a camera. Analysts believe that Apple can sell as many as 5 million of the tablet computers in the product’s first year. Prices range from $499 for a 16GB WiFi up to $829 for a 64GB 3G+WiFi unit.

Some of the biggest enhancements to the business computing experience will come from Apple’s applications at first. The company promises a Mail experience that will let users “see and touch your email in ways you never could before. In landscape, you get a split-screen view showing both an opened email and the messages in your inbox.”

The iPad’s Calendar tool takes a big step toward the functionality of the DayTimer and DayRunner journals of the 1990s. The landscape format and portability, along with the utility of managing several calendars at once, take the mobile device into the realm of portfolios we carried from meeting to meeting.

Apple’s refreshed a Web page that summarizes the initial value of investing in this business tool. The marketing copy focuses on the applications that will be available as included software.