Do you think this would be a good market to build a product or set of products for? Do you have experience working in the non-profit sector to support your claim?
Let me know! michael[at]faceaids[dot]org
TechSoup (where I used to work) helps greatly with the acquisition of commercial products, like Windows and Office, by partnering with the vendors to lower the cost to a fraction of retail.
Aside from your back office and IT stuff, the other two big needs seem to be Web site development (for outreach), and CRM (to manage donors). Drupal, Plone, Joomla and other solutions are popular for the former. CiviCRM is popular in the latter, as are solutions from Kintera and Convio (for large orgs with the money to spend.)
This is not to say that all nonprofit tech needs are being met. But it's definitely a busy space. If you're looking to get involved, it'd be good to find a problem that isn't yet being addressed and attack that.
If you haven't already, you might want to join NTEN (http://www.nten.org). And keep an eye on Aspiration and attend their next NPO Software Developers summit. (The 2008 summit in Oakland was last week.) http://www.aspirationtech.org