Web 2.0 is a frequently used term, and it is difficult to pin down any sort of definition.
Taradata see's Web 2.0 as a set of technologies and concepts that move the web onto a different level of functionality and interoperability. This means that internet users experience and expectation is now much higher. They will not tolerate the old boring sites of yesteryear and want exciting, dynamic sites that provide them with a more complete experience.
Our focus is is to understand your business, what you are trying to achieve, and the markets that you are trying to address. From this we can establish your needs and choose the appropriate technologies be it Flash, SliverLight, Ajax, DHTML, XHML, XML, RSS, Web Services etc that are required.
As always the business is the driver, but it is essential that your site delivers a level of experience that is appropriate for your audience.