What is an HDMI input?

Please tell me how I can use spdif RCA to my Lexicon and bypass the audio portion of HDMI?

...from what source?

I heard that what we have now is HDMI 1.1 but that a more advanced HDMI 1.3 is expected soon (higher resolution 5.1 digital audio). Can anyone shed any further light on that? For me, it's the (all too familiar) hesitancy to invest in something now that may be outdated relatively quickly.

As an addendum to my previous post, if you do a Google search for "HDMI 1.1, HDMI 1.3" there are many questions out there regarding the possible obsolesence of the current HDMI 1.1 when the 1.3 format comes out. I hope I'm not breaking any rules by pasting these, but here are some excerpt quotes from the top few Google listings:

***...When asked why, Hipps responded, "HDMI is a moving target. With the HDMI 1.3 standard probably 2 years away, any of today's HDMI devices risk obsolescence. Rather than have a $4,000 audio receiver be viewed as obsolete because it can't support HDMI 1.3, we'd prefer to offer..."***

***(5) HDMI v 1.1 is already hitting the shelves, with v 1.2 on the way, and v 1.3 in the next couple of years (v 1.3 will deliver higher res 5.1 digital audio). What will be the backward compatibility of these versions?***

***...Also as I am sure you are all aware the standards have not settled down yet 1.2 has just be ratified but they are now working on 1.3, so introducing a decoder that will be out of date very soon didn't make sense...***

I'm having difficulty finding a straight answer on this.
The actual (official) HDMI website is here: http://www.hdmi.org/
But even here I couldn't find clear answers regarding issues such as backward compatibility etc. of 1.3 with today's 1.1.

Anyone?

http://www.superaudio-cd.com/newsitem.php?=88
Looks as if HDMI 1.2 will handle both sa-cd and dvd-a 5.1.