You've been involved in multiple migrations to OOo. What's the typical profile of a company choosing for OOo?
I can hardly tell about a typical profile, but many migrations are run by public administrations. Medium to large companies are more and more interested in OOo for economical reasons. All in all many companies are evaluating OOo because they pay attention to what's new, since OOo is still in its early adoption phase.
What are real the advantages for an SME to use OpenOffice.org?
OpenOffice.org is legal, and you don't need to bother with proprietary licenses. It means that any SME can be autonomous in choosing when (and if) to upgrade to the very last release of the suite. As with every other open source package is up to the customer to choose what to buy, and from whom. It's matter of independence.
Are these advantages also the incentive of the switch, or do people only focus on price?
Price is a key factor, but if it is seldom the only reason to switch. Interoperability, namely OOo's ODF compliance, is often another good reason to move to OOo. A lot of users are realizing that they are using a tiny fraction of Microsoft's office functionalities, and that all of them are offered also by OpenOffice.org. Moving to the new Microsoft office suite is not painless, and it counts indeed.
Most commercial tools are designed to integrate with Microsoft Office. Isn't that a problem for companies using OOo exclusively?
It is for medium to large companies, since they typically use a lot of enterprise applications (SAP, etc). The most frequent issue is interoperability with custom applications, though.
OOo has an interface resembling the one from Microsoft Office. Shouldn't OOo clearly differentiate and bring new ideas rather try to mimick the leading Office suite? After all, Firefox succeeded by bringing or popularising new things to the browser.
I think that to make OOo interface resembling the Microsoft Office's one was a great move. People is familiar with it, and moves smoothly from a suite to the other. Christensen calls it low-end disruption, a disruption targeting users who do not need the full performance valued by customers at the high-end of the market. But OpenOffice.org now offers users the possibility to add functionalities through "extensions", and I think that we are going to see many of them in the very next future.