I read the SVG Integration 1.0 draft. In section 2.7, It asked "should we have an Immediate Mode?" and I think that yes there should be an Immediate Mode.

Although this option would rarely be used and is probably a corner case on the web, there are situations where it can be useful. Specifically, an SVG document can be used as an image texture or sprite sheet inside of another application.

Also, the Immediate Mode could be used for weak references in image caches, and for server-side image transcoders that need to convert an SVG Document into another image format without much processing power that would slow down the web host, or when a programmer is programming an interaction between an SVG Document and a native graphics library -- perhaps content embeded inside of an interactive plug-in using Applets, or Flash, or some similar plug-in.