I don't think we'll see a price point change, rather I think we'll see 3 NEW introductions.
MacBook and MacBook Pro will be brought together into one line (That's iffy as people like to buy "special" editions and anything with a Pro/Mercedes/Lexus name is going to have that "special" feel).
But I think we'll see a $799 or $899 MacBook laptop with lower specs possible sans optical too. I see a need or rather a market for a 13 or 12.1" screened notebook with decent specs, no optical, rather long battery. Every students dream machine. The ability to use for 8-12hrs without charging. I know 3 people who in college had to carry 1-3 extra batterys for their iBooks. Then had to get up every 3hrs over the night to switch them out (a multi charger would have been used if it were me).
PREDICTION: 14.1" screens will replace the 13"s. There cheaper and have the same specs. With LED lighting they would fit in the current gens frame and provide those magical words Steve likes to use "??% Larger and were keeping the same price". 1440x900 will be the standard resolution. EDIT: The 13.3's are actually capable of it too... Soooo maybe I'm wrong...
Then a $1099 price point- gain better equipment standard and go up. A $1599 14.1" Pro-speced unit with dedicated graphics card (#2).
And what I AM PERSONALLY hoping for... (#3) a $599-799 10" screened mini-note ultra portable notebook. I just sold my 7" unit so I need a new one. I'll wait till the 14th but this really seems like such a breakthrough like produce it would be waitable till Macworld. Intel Atom powered unit with intel graphics is fine. Through in a 32gb SSD or my fav a 120gb 7200rpm 1.8" drive and you'll see one of the hotest selling macs in a long time. Of course 5400rpm drives are fine too, this unit MUST meet a 5-6hr battery life MIN.
As for desktops, we'll see a spec bump change across the board. Anything drastic right now is a little too soon, except the Mini. I LOVE the mini for everything it is and everything it can be. But the current specs... Drop the price $100 and we'll call it a fair deal or give me uprated cpu's and a higher ram limit with slightly more graphics. I'd rather have the price cut though because for what it is, it is fine. I need to purchase 24 of these next month for a customer and that's $2400 less which could go towards the purchase of peripherals and/or parallels software.