The Xonar HDAV 1.3 might the first sound card to claim to full HDMI 1.3a support, but ASUS has a few more tricks up their sleeves that could make it interesting to non-audiophiles. The Xonar is capable of performing some corrective post-processing effects on HD video with its "Splendid HD" chip, saving precious CPU cycles.
The guys over at AnandTech got a brief hands-on at Computex and tested the noise reduction and contrast filters, which performed as advertised. The card also fully supports DTS-HD Master Audio and Dolby TrueHD for Blu-ray, which makes the Xonar an attractive solution for home theatre DIYers. ASUS plans to ship the card in July, but there's no word on pricing yet.