My take on this, for what its worth - some of this has been said before, but I'm just summarising...
If they increase the iBook to 800 then they HAVE to do something to the Ti - Apple has consistently maintained a "gap" between the iBook and Ti in terms of Mhz (some would say to the detriment of the iBook - 1.2GHz G3 anybody??). To me this suggest a minor speed bump (ie not to 1Ghz) for the Ti as well as the iBook. The fall in inventory, as others have consistently pointed out, also suggests an update, not just a price drop (although both would be nice).
Minor speed bump now and then something better in SF?? Simple answer is "I don't think so", I think we'll have to wait until after SF. However, if they do choose to announce something in SF, two possibilities spring to mind and of the two, I think the first is the more likely.
1. As suggested earlier, Steve announces addition of Superdrive with an upgrade programme for people who bought in 2002 - something similar to this HAS been done before (although I'm not exactly sure of the timings) when they speed-bumped the Ti and then brought out the Combo and upgrade programme a few months later
2. Bit of a shot in the dark this, but if the person who originated this story really HAS seen a 16 inch Ti, how about a "top of the range" Ti (aka the 14 inch iBook) 16 inch Ti with internal Superdrive announced at SF and available in Feb/March 2003?? If they charge enough for this (and knowing Apple if this is anywhere near to the truth then they most ceretainly WILL charge hugely for this), it shouldn't cut into the "normal" Ti sales too much (hey the debate about 12 and 14 inch iBooks is still going strong ("I prefer the 12 inch/no the 14 inch is better" etc etc)). Better graphics, higher resolution, bigger/faster HD, more RAM etc and Bluetooth as standard.
This option would also see the "matrix" evening out a bit more - 3 desktop models for education, consumer and professional (e-Mac, iMac and G4) and then the iBook becomes an "educational" model with the standard Ti being the consumer and the top of the range Ti being for professionals. This would also neatly get round the "I want a G4 in my iBook" problem if they reduced the price of the standard Ti so that more people could afford it. As I said, I don't think this will happen, but you never know...
Just my 2c as they say - all will be revealed soon...