“The manufacturing cogs for the tablet are creaking into action,” writes Oppenheimer’s Yair Reiner in a note to clients issued Wednesday morning.

According to his supply chain sources, Apple (AAPL) appears to be gearing up to build as many as 1 million tablet computers per month. Assuming the company would need 5 or 6 weeks of inventory before going live, that suggests — barring production hiccups — a March or April 2010 launch.

Among the other “tidbits” Reiner says he’s picked up:

• Apple has settled on a 10.1-inch multi-touch display using the iPhone’s LTPS LCD technology, not the considerably more expensive OLED technology suggested in earlier reports.
• Apple has been approaching U.S. book publishers with what Reiner describes as “a very attractive proposal” for distributing their content: an App Store-type 30/70 split (30% for Apple) with no exclusivity requirement. [See UPDATE below.]
• According to Reiner, publishers are disgruntled by Amazon’s (AMZN) terms, which force exclusivity, disallow advertising and demand a “wolfish cut” of revenue. The typical Kindle/publisher split, he says, is 50/50, rising to 30/70 if Amazon gets exclusivity.
• Apple’s tablet would make ebooks more attractive for the education market by simplifying functions such as scribbling marginalia.

“We have not adjusted our model to show the impact of the tablet,” Reiner concludes, “but we believe it will be substantial. Conservatively assuming 1M-1.5M units per quarter at an ASP of $1,000 and a corporate average net income margin of 22%, the tablet could contribute $0.25-$0.38 of incremental EPS per quarter.”

An average selling price of $1,000 seems a little steep for the college market. But if Reiner is right about the timing, we’ll find out soon enough.

UPDATE: In an interesting twist that might be related, the
Wall Street Journal
reports today that Simon & Schuster is delaying by four months the electronic-book editions of about 35 leading titles coming out early next year, and that a second publisher, Lagardere SCA’s Hachette Book Group, has similar plans in the works. According to the Journal, S&S is “taking a dramatic stand against the cut-rate $9.99 pricing of e-book best sellers.”

For more artists’ renditions of what Apple’s unnamed and unannounced tablet computer might look like, see Silicon Alley Insider’s gallery here.

[Follow Philip Elmer-DeWitt on Twitter @philiped]