Like the other responder caw I think it depends on your business, and it also depends on your target audience. Open sourcing the wordpress blog platform? Sure

Like the other responder caw I think it depends on your business, and it also depends on your target audience. Open sourcing the wordpress blog platform? Sure that makes sense, the target audience for wordpress are largely technical (to a greater or lesser degree), and want to see what they're putting on their servers. More importantly they want to customise it without limitation. Open sourcing a productivity application? Hmm, not quite so clear cut. If the majority of your users are technical that's good. But are your users going to want to fiddle with it to the extent that they want it open sourced? I'm really not confident that they will unless you know something about them that I don't? In other words, what is the benefit to your customers in your app being open source? To answer your other questions...I don't think that you'll get more press coverage about your project just because it's open source. Open source isn't a new thing. My personal view is that I would launch your app paid for using one of the standard pricing models. See if you can gain traction on the benefits of the app alone, rather than trying to put an open source twist on it at the outset.