BTW, I should have added that having Flash isn't always the greatest thing. I have it on my Nexus One, and it takes up a lot of storage space (may not be a problem on WP7), but it also only works so-so, and sometimes makes mobile browsing even more annoying. I tend to keep it turned off until I find instances where I absolutely have to have it.
Windows Phone 7 applications (except 3D games) are usually built using Silverlight. However, I don't think it supports the Silverlight browser plugin.
You are correct. I should have been more specific and just said the web browser.