We've known all along that we needed a native vector graphics format (for 
clip art, etc. in AbiWord, and perhaps for charting in AbiCalc) to go along 
with PNG as our native raster format, but it's a sizable enough job that 
we've been quite willing to ship 1.0 without the feature if need be.  
The thought of an XML-based vector graphics format has always been 
tremendously appealing, for obvious reasons.  We've already got expat (for 
parsing XML) and GR_Graphics (for abstracting out all the drawing work), so 
"all" we need is a whole bunch of code in between, right?  ;-)
Rather than pick between the PGML and VML camps, we've pretty intentionally 
sat on our hands waiting for a standard to emerge -- ideally with some good 
GPL-compatible (preferably XP) code attached.  
It looks like this was a good move.  As Havoc points out, SVG is the 
"consensus" format being developed by W3C to replace the earlier PGML and 
VML proposals.  I don't think anyone on the AbiWord team has evaluated the 
spec technically, but I bet that with folks from both camps on the working 
group, it should be plenty big enough to have whatever features we might 
need.  (And then some.)
More specifically, at LinuxWorld back in March, Adobe's Bruce Hunt was 
evangelizing us to support SVG as our vector graphics format, and pointed us 
at the following potential sources of non-proprietary code:
  - a reference implementation based on the Java2D APIs
  - Peter Deutsch (Mr. GhostScript) 
Again, to my knowledge, nobody else has tracked down either of these leads, 
but I know which sounds more appealing to me.  :-)  
Paul