Firstly, in order to get access to Dallas, one needs to get access the Dallas Developer Portal. It's still not in the phase of open-for-all where anyone can sign up and get access. As of now, we can get access to Dallas as on invitation basis. Go to this portal, request your invitation code (its just a matter of dropping an email with a request to receive invitation code). Generally one should receive the invitation code on the very next day.
Log on to this portal, and you would be provided your account key. Save this key securely at some place, though this would remain available to you on your account home page on this potal. This key is important as this would be used as a kind of GUID for billing and reporting. The question that comes now is billing what and report what ? This is the next part of Dallas.
As per what I understand and anticipate is that, Dallas would offer content in the form of structured datasets from a lot of content providers in the form of a service. These content providers would be business houses, who would provide respective content which can be images, text or any blob kind of data to their subscribers. Using Dallas, one can subscribe to their service of choice.
Presently this portal provides a "Catalog" tab which shows a list of service providers to which we can subscribe. Subscription is free for the trial period. After you have subscribed, there is another tab called "Subscriptions" where you would be able to find your subscriptions. Under each subscription, you would be able to find a link that says "Click here to explore the dataset". Once you click on it, you would be able taken to Service Explorer page where it provides a set of parameters to specify your criteria and a few action buttons to view the data. This can be thought of much like a accessing or testing an invoked web-service. You can preview the data, as well as download it to analyze with powerpivot (provided if it's installed on your machine). The dataset that this service provider would return, would be limited to 100 records which is limit set for the trial. One nice thing is that it offers the service class readily to download to that service, so developers can just add a reference to it in their applications and business can start accessing it in their own hosted environment.
The last tab on this portal is the "Access Report" tab. On this tab you can view the reports of how many times you accessed each subscription service. And to the best of my thinking, you would be charged as per the usage of each subscription. I have not learned much about the pricing policy, so can't comment really much about it.
Finally it comes to how this can be used for Business Intelligence. Business Analysts keep of accessing and aggregating data from different sources, and most of the premium content providers charge a fees for the subscription. One of the best examples is in the Equity Research Business, where data from a lot of sources is studied for each equity. The same concept can be used here but it should be pay-as-per-use in my understanding. Using the cloud platform, applications and data storage can all be hosted and stored on the cloud instead of investing IT resources for the same. And using tools like powerpivot, data from various different business sources can be aggregated and analyzed without investing major IT resources for the same.
Still this does not eliminate the need of IT technology workers (coz I am one of them), as they would be the one who would be facilitating this setup for the business in IT environment to reduce manual efforts and program regular analysis routines !!