Whether they will be released or not, they will use ROS v3.0 which is still in beta release.. I think first v3.0 should be completed before releasing these products...I wasn't at the Egypt MUM so I don't know what happened there.. But I do know some specs from the Orlando MUM..
RB600 is going to be 600-666mhz ppc cpu, 3 gigabit ethernet, 4 minipci, 2 compact flash slots, support for daughter boards.. not sure on memory but I'm just guessing it'll be 128.
http://forum.mikrotik.com/viewtopic.php?f=3&t=15246
Reply from Edmunds 2 days ago..
"RB600 should be available in the beginning of December, RB411 - in February, 2008."
-Gerard