if the DrivePool is not necessary for MythTV, then separate drives wouldn't matter.
Disk Usage Summary: Total Disk Space: Total Space: 7,714,199 MB Space Used: 4,934,035 MB Space Free: 2,780,164 MB Space Available After Auto-expire: 2,792,900 MB Space Used by LiveTV: 1,124 MB Space Used by Deleted Recordings: 11,612 MB Space Used by Auto-expirable Recordings: 0 MB Disk Usage Details: MythTV Drive #1: Directory: jmd0:/mnt/mythtv/hitachi_2t_3_0/recordings Total Space: 1,870,843 MB Space Used: 456,439 MB Space Free: 1,414,404 MB MythTV Drive #2: Directory: jmd0:/mnt/mythtv/jmd0_vg_2t0_0/videos Total Space: 1,511,771 MB Space Used: 1,030,614 MB Space Free: 481,156 MB MythTV Drive #3: Directory: jmd0:/mnt/mythtv/jmd0_vg_2t2_0/videos Total Space: 503,838 MB Space Used: 44,975 MB Space Free: 458,862 MB MythTV Drive #4: Directory: jmd0:/mnt/mythtv/jmd0_vg_2t3_0/recordings Total Space: 1,907,729 MB Space Used: 1,569,150 MB Space Free: 338,578 MB MythTV Drive #5: Directory: jmd0:/mnt/mythtv/jmd0_vg_2t4_0/recordings Total Space: 1,907,728 MB Space Used: 1,832,828 MB Space Free: 74,900 MB MythTV Drive #6: Directory: jmd0:/tmp/mythtv Total Space: 12,288 MB Space Used: 26 MB Space Free: 12,261 MB
Number of shows: 299 Number of episodes: 7734 First recording: Sunday May 30th, 2004 Last recording: Friday March 14th, 2014 Total Running Time: 9 years 9 months 14 days 15 mins Total Recorded: 11 months 14 hrs 2 mins Percent of time spent recording: 9%
Stablebit 2.0 is out and works on platforms other than WHS2011. You do want to stick with the latest 1.x version if you use WHS2011.
Stablebit 2.0 is supported on Vista and later MS OS. 32 and 64 bit. (Non Windows RT versions of course)