Today’s Amazon news release on the launch of its Kindle for Blackberry App provides the first direct and official confirmation that the company will also soon launch a Kindle for iPad App. Here’s the second sentence from the lead paragraph of today’s release:

Amazon’s Whispersync technology saves and synchronizes a customer’s bookmarks across their Kindle, Kindle DX, iPhone, iPod touch, PC, BlackBerry and soon, Mac and iPad, so customers always have their reading material with them and never lose their place.

While it was previously evident for anyone who wanted to connect the dots, the specific statement that a Kindle App is coming soon for the iPad (along with the Mac App that has been “coming soon” since 1974, or at least since November) is a clear indication of something we should not forget: Amazon and Apple may be adversaries or competitors, but they are also business partners on what is or will eventually be a multi-billion dollar level.

The Kindle for iPhone App and Amazon’s Stanza app are already two of the top three reading Apps in Apple’s Apps Store for the iPhone and iPod Touch, and there is little reason to doubt their capacity to sustain high market share among iPad users. The Kindle Store currently accounts for upwards of 90 percent of all ebook sales, according to widely published reports from unnamed publishing industry sources.