Adobe is announcing the Touch SDK as part of an extravaganza of Creative Suite news tonight that includes the announcement of Creative Suite 5.5 (an interim upgrade due within the next month with a bunch of new features, many of them focused on creating Flash and HTML 5 content and apps) and the introduction of subscription plans that will let users opt to pay monthly fees for ongoing access to the latest versions of the Creative Suite apps rather than buying them the traditional way (prices range from $35 a month for one app, such as Photoshop, to $129 a month for the Master Collection, which includes everything). Creative Suite 5.5′s version of Photoshop will support the SDK, but you won’t need to upgrade to it to use Photoshop-enabled tablet apps: Adobe will make a free update available for Photoshop 5.5 on May 3rd, the company says.

(The launch of Creative Suite 5.5, incidentally, introduces a new update schedule for the suite: Instead of releasing a major overhaul as often as every eighteen months or so, Adobe intends to release a big one every two years, with a smaller interim one coming in between. That means that the company will never be more than twelve months away from being able to add new features.)

You start using Touch SDK-enabled tablet apps by turning on Remote Connections within Photoshop–which involves creating a password–and then pairing the tablet apps with Photoshop so they can communicate with each other over a Wi-Fi connection.

Adobe has built three iPad apps that utilize the Photoshop Touch SDK, all of which it says will be in Apple’s App Store in early May. The company provided me with early access to them and to the new version of Photoshop that supports the SDK.

Adobe Nav is a navigational aid that lets you choose Photoshop tools and jump between open images by tapping oversized thumbnails.

Eazel lets you do watercolor-like painting, then zap your creations into Photoshop.

Color Lava is a color mixer that lets you mix custom colors on the iPad with your fingers, then transfer them into Photoshop.

Nav is pretty darn nifty, especially the feature for bopping between open files, which makes a common task way easier than it is using Photoshop alone. Eazel and Color Lava are okay, but they feel more like proofs-of-concept than full-blown, well-rounded apps–both are interesting, but they’d benefit from more features, more straightforward interfaces, and a bit of online help or other explanation. Adobe will sell them on Apple’s App Store (for $4.99 and under apiece) and will, I hope, beef them up over time. But I wonder if it might be more productive to give them away to get Photoshop users and developers excited about the possibilities of the Touch SDK.

And clearly, the big idea here isn’t Adobe making money by selling tablet apps–it’s to get other developers building Photoshop compatibility into their tablet creations. I think the potential exists for some cool all-new programs centered around the Touch SDK, but it’ll be at least as cool if the creators of existing graphics related tablet apps such as Brushes and Artrage use the SDK to connect turn their programs into extensions of Photoshop–and vice versa.

The basic concept behind the Touch SDK isn’t all that Photoshop-specific; other Creative Suite programs such as Illustrator and Premiere could benefit from similar integration with tablets. Adobe isn’t announcing anything about extending the SDK to other apps, but it acknowledges that it’s an intriguing notion.

Actually, programs of all sorts from other companies–word processors and e-readers, for instance–could use SDKs to utilize tablets in helpful ways. If this catches on, tablets could develop a second identity as a whole new type of input device that’s sort of like a second monitor and sort of like a Wacom-style pen tablet (but with no pen involved). The idea isn’t without precedent–a company called Informal Software, for instance, tried something similar with Palm PDAs more than a decade ago–but maybe the time is finally right. It’s certainly far more appealing with a big tablet screen than a little PDA or phone one.

Safari 4 is blazingly fast.

Google explains yesterday’s Gmail outage.

…and Gmail users get phished.

Google joins European Microsoft tussle.

Is your congressperson on Twitter?

Intel says thin is in.

AMD demos six-core CPU.

A big Photoshop bug fix.

Microsoft’s stock isn’t so hot.

Google updates Internet 6 Toolbar.

Roy Blount wants Kindle cash.

Samsung writes a Memoir (phone)

Nokia music phone hits stores.

Will the Kindle go international?

Another roaming-charges horror story.

Adobe patches up Flash vulnerabilities.