For some time now we've been expecting the successor to the FT817 to appear on the market as the current offering is now over 10 years old, with just a minor update in this period. Sunspots are rising fast now and I'd expect Yaesu-Vertex to release this within 6 months or miss a big window of opportunity. The potential sales volumes are very large indeed as a large part of the amateur community owns an FT817 and would aspire to upgrade.
One wonders how Yaesu-Vertex is viewing the Elecraft KX3 and whether any changes to their new product will be made as a result of the KX3 pre-release data. The KX3 does look impressive but its form factor may not appeal to many. It also looks very "square" and Elecrafty! Although it can be used handheld, I understand you have to plug in a local microphone for example - a bit clunky for true handheld portable use, although you need an external mic with the FT817.
It is widely assumed that an FT817 successor will have a Li-Ion battery pack (2hr charge), built-in wide range auto ATU, good DSP features and possibly 70MHz coverage. The form factor is unlikely to be very much different from the current model, but with more inside.
Does anyone have any inside knowledge of Yaesu's release plans? If they don't get a move on the KX3 will steal the show. The KX3 is due to be released at the end of 2011 and order placement is starting very soon.