Just point your BlackBerry's browser to the URL above and you can download the latest version of Yahoo! Go. I just installed it on my phone (962kb download - make sure you have a good data plan!) and in the few minutes I have spent with 3.0 I can definitely say that it seems to be quicker than its 2.0 predecessor (at least on my Roger's Edge connection), though overall it still seems a bit slow to me.
The big difference with 3.0 is that Yahoo! is opening up the application to include support of 3rd party Mobile Widgets - you'll be able to add Widgets to your Yahoo! Go carousel for all kinds of non-yahoo content (MTV news, MySpace, eBay are there to begin with). For myself, Yahoo! Go has always been one of those apps that I install, like the look of, and then never use. I'm not really a Yahoo guy, so I'm not sure that 3.0 will be any different (for me), but if a lot of widgets become available I could see it getting a lot more love on my BlackBerry. For people who don't like to hunt down and install apps, 3rd party widgets will allow one to expand the use of their phone easily which is a great thing. I'm curious to know what you think of it! Loving it? Let us know your thoughts!