We are aware of this. The reason sited by Adobe is that all the popular browsers, with the notable exception of Internet Explorer (versions older than IE9) now support SVG natively and that there are a number of other plug-ins available.
PPO supports Internet Explorer, Firefox, Opera, Safari and Google Chrome browsers.
From our point of view however the continued support of SVG in Microsoft Visio is critical and as far as we are aware Microsoft has not indicated that they will be dropping this support, nor do they currently support the export of Visio files to XAML/Silverlight.
"SVG support is something that we have been evaluating for some time," Microsoft said in a statement. "We recognize the demand for vector graphics from Web developers, and realize this is a high-priority demand."
We will take whatever action is required to ensure that clients with older browser versions are not affected.