Just to correct the original post. Denon has the Best Digital -> Analog converters on the market, and have had this distinction for the longest time.
In fact Denon has been leading the way in all of their electronics, though they trade this for a lower quality amps. This has been their distinction for a long time. Many other companies focus on the AMPS, rather then the electronics. Remember DVD's are a 5.1 mp3 standard.
I hear that HD and BlueRay have upped the standard with higher quality sound compression.
Personally HDMI is a cool tech. Its nice to think that Digital -> Analog -> Digital on a video system will create a low quality image, and that a Direct Digital signal to the LCD/Plasma will create a better image quality.
However I have seen that in the computer market, DVI verse Analog has very little benifits. DVI is a Digital Video Standard, Like HDMI; however the Analog signal is a VERY old standard on computers (Like 20 years old).
I have seen almost no distinction, and any difference is VERY slight. NOTE: In computers we use MUCH higher resolutions then HDTV.
That coupled with the fact that HDMI is not a solid standard, I would recommend not rushing to get a HDMI A/V receiver. I fear that if you do, you will find yourself stuck with an outdated HDMI standard that does not work well with the new equipment.
I have also heard reports that the switching on many A/V Receivers is not as solid as it could be. This coupled with the fact that Cable companies dont support HDMI yet, and most DVD players do not either. Thus you will either have receivers with either too many or too few HDMI sources.
My suggestions is to wait. Give the HDMI world a few years to develop.