Phew, it took me a while to get here, but I was able to successfully capture canbus data from my 2012 Honda Odyssey and then play it back to an extra instrument cluster I had lying around.
Test rig:
I built a simple test rig by learning the pinout of my Honda Odyssey cluster. It is a 32 pin connector. For purposes of this test, I used 2 12V power lines (pins 1 & 17), 3 grounds (pins 4,31, 32), HSCAN+ and HSCAN-. There are pins for low speed CAN (125kbps) but I am not playing with those yet. The setup is powered by 8 AA batteries. I added a 125 ohm resistor between the data lines on my breadboard.

Using socketcan-serial, I ran "candump -l" which is part of the socketcan Linux utility. I drove for about 15 minutes and captured 59 mb of packet data.
Next comes the fun part...I ran canplayer -I [filename] to play my data into the test cluster. Voila, the cluster showed the RPM from the start of the file!
Unfortunately the fun only lasted for a few seconds, as I keep getting a "no buffer space available" error. The only way to clear it is to turn the cluster on and off. Any suggestions on how to fix this? The output below might be interesting. Also here is a movie showing the tach move!
parallels@ubuntu:~$ ip -details -statistics link show can0
5: can0: mtu 16 qdisc pfifo_fast state UNKNOWN mode DEFAULT group default qlen 10
link/can promiscuity 0
RX: bytes packets errors dropped overrun mcast
638465 80715 0 0 0 0
TX: bytes packets errors dropped carrier collsns
198 29 0 0 0 0