Unless you plan on buying alot of cheap HD DVD movies- I wouldn't look at a toshiba for up conversion. Reason I say this is you already have a VERY good player in the oppo 980 (I own one too) and it's well known that the 720p pannys look very good with SD- I'm not sure how much of an improvement you'd really see, if at all.
On my 37" 720p olevia LCD any differences between my oppo and my HD-A3 are nearly impossible to spot. With the increased size and resolution of my 46" 1080p panasonic plasma, however, the oppo gains the edge with it's ability to output 1080p and thus avoid the relatively mediocre de-interlacing in my panel. It makes fast-action scenes and fight sequences much crisper than the toshiba. Still, differences are slight and only noticeable when doing a side by side comparison.
The XA2 was supposed to have superior upconversion with it's HQV processor- but they are still going for 300 used! I just ordered a samsung BD2500 blu ray player that is also equipped with the HQV- new- for the same price. Now, before the xa2 owners take offense, i'm sure the XA2 is a better built piece of equipment... But it doesn't change the fact it is a discontinued product on a dead format.
Point is, if you want to take advantage of some of the excellent deals on HD DVD discs, buy the cheapest player you can find, like an A2/A3... If you can find something better for the same price, go for it. But don't spend too much as it negates the deal, IMO.
"For small creatures such as we the vastness is bearable only through love."