We have kind of already done this: http://www.thegrantat250.com

There are 16 spaces all together. One of them is a cafe. A few of them are retail. The bulk of them are design-related businesses of one or two people each. There is also a small art gallery. We have been open for a year. There has been some collaboration already, between businesses to work on larger projects. There is a recording studio with a vocal booth that does mainly hip hop artists but that can also record for web voice overs. We have an architect who has hired one of the designers to do a new website. We have designers that use the silkscreen studio's offerings for apparell printing and poster printing. All in all, it's worked pretty well.

We finally have a shared conference room ready to go for people. Internet is included in the rent, and WiFi is available.