1. By the end of 2011 the majority of Printed parts sold on Ebay will be of the Prusa instead of Sells Mendel variety.
2. Ultimaker will be released by Erik, and he will have found a solution for the latency issues of the bowden extruder, which will drastically improve the build quality of those style extruders (and paste extruders)
3. RAMPS by Ultimachine will continue it's improvement, and become the de facto of electronics for RepRap in 2011 as Gen3 by Makerbot was in 2010. RAMPS will have HBP, Multi Extruder, Bluetooth, Print from SD, and be a SMD board.
4. The wedge "Mendel" design will continue to be the mainstay of RepRap design though 2011 for FDM, but RepRap will officially add a pic-n-place either detla or arm based, and a "offical" CNC Router design.
5 The Makergear Prusa Kit will become the most popular "RepRap" kit, because Makergear is the only kit seller that does not rely on forums to do their Tech Support. Relying on Forums/Wiki for tech support isn't community; it's just lazy/cheap if the seller is not active in that wiki/forum.
6. By the end of 2011 more 1.75 filiment will be sold than 3mm.
7. Makerbot will offer a commerical "plug and play" 3d printer in 2011. It will retail between $3000 - $4000, and will use the Gen4 Electronics. I think Gen4 was not designed for Thing-o-Matic (it could have been run on Gen3 or Ramps just as easily). Gen4 I think is the brain for that industrially manufactured non kit printer, and Thing-o-Matic is being used as a field test for those electronics. I don't believe Makerwave is dead yet.
8. Legal action will be threatened against Thingiverse some time in 2011 for distributing proprietarily designs. It will make big news in the real world.
9. By the end of 2011 more of the "who is making what" photos on Thingiverse will be RepRap printed than Makerbot product printed.
10. Before the end of the year the average cost for the RP parts for a full sized 20x20cm print area Mendel will be $75 (with some being as cheap as $50), full "kits" will be available for $550, and fully integrated and tested RepRap will be avialbe for $750.
11. Someone is going to offer an injection molded 3d printer before the end of the year.