Here is a letter from Twitter CoFounder Biz Stone.  I’m calling it the ‘micro-updates’ to communicate to their community.  This is a great sign on top of a good week where Twitter put the stake in the ground and firmly ratifies their commitment to developers.

Message microupdate from @biz Biz Stone

Hi there,

In the early days of Twitter, I used to send out short updates just to keep everyone in the loop since so much was happening. It’s been a while, but you signed up for short, monthly updates from Twitter so we thought it was time to start sharing more information. We’ve had quite a year. If you haven’t visited in a while, we’d like to invite you to come have a look at http://twitter.com — we’ve been busy!

Growing Up
In the course of a year, registered Twitter accounts have grown more than 1,500% and our team has grown 500%. Recently, we hired our 140th employee! His name is Aaron and he’s an engineer focused on building internal tools to help promote productivity, communication, and support within our company. We celebrated with a little dance party.

Features of Note
Some features of note that we released over the course of a year include the ability to create lists, quickly spread information with a retweet button, and an easier way to activate your mobile phone to work with Twitter over SMS. We also built a new mobile web site that looks and works much better on smart phones.

Feeling Inspired
By working together during critical times when others needed help, sharing important information that otherwise might not make the news, and inventing new and interesting ways to use Twitter, you’ve shown us that Twitter is more than a triumph of technology — it is a triumph of humanity. Projects like Fledgling and Hope140 were inspired by you.

Chirp!
While there may only be 140 full-time employees working at the Twitter offices, there are thousands of dedicated platform developers who have now created more than 70,000 registered Twitter applications creating variety and utility for all of us. We’ll be gathering this spring at Chirp, our first ever official Twitter developer conference.

Thanks,
Biz Stone, Co-founder (@Biz)
Twitter, Inc.