It’s being called a first for corporate communications. Late last night Sun Microsystems CEO Jonathan Schwartz broke the news of his resignation via Twitter.

In a succinct haiku delivery, Schartz wrote: “Today’s my last day at Sun. I’ll miss it. Seems only fitting to end on a #haiku. Financial crisis/Stalled too many customers/CEO no more.”

Schwartz’s departure from the company recently acquired by Oracle was no great surprise. Just last week Oracle CEO Larry Ellison said he expected Schwartz to leave. But, just as he did with his personal blog and his campaign to make the SEC allow blogs to have equal standing with traditional releases when conveying business news to investors, Schwartz has once again challenged the conventions of corporate communication by taking his thoughts direct to the Twitter universe.

Suitably, news of Schwartz’s Twitfeat has already been retweeted over 1000 times to milions of “readers”, unfettered by the spin of an official Oracle’s press release. How’s that for effective C-Tweeting!