I was able to get the AverMedia Java Viewer to install on my Blackberry 8900. I was trying to install from an EB3004Net SATA+. The trick was to download the JAVA-Viewer.jar (located at the box's install link http://DVRIPaddress:5550/JAVA-Viewer.html) to a computer first, then email it to yourself. Once it shows up on your blackberry, click the attachment and choose open. It will then prompt you to install. I was able to install correctly using this method.
Previously i was running into a Error 907 invalid JAR (something about missing trailing bytes; whatever that means) when trying to install using the blackberry browser.
I will note that it does work, but the resolution video feed doesn't scale to fit modern blackberry resolutions...on my 8900, it was approx 1/9th of the screen (guessing approx 160x120px), so you need a magnifying glass to see it...but better than nothing! I did speak with an AverMedia support tech who stated that they are expecting to release an updated Java Viewer this summer 2010.
Bottom line, install it by email and you should be good to go.