What % of Shared Hosting Package Provide SDO XML DAS Extension installed. or has the capability to install it for the User. i.e. If my Application makes use of SDO XML DAS would I be able to work with it on any Shared Hoisted Server ?
You're hardly going to get any hard numbers on this, as there is no central registry for which provider has which extensions installed.
I wouldn't count on this extension to be present, though. I just checked with my main hosting provider who is very generous with memory limits and installed extensions, and it's not there. Hosting providers are hardly going to install this for a single customer, neither.
If you want your software to be as portable as possible, I would not advise to make use of this extension.