I believe I can offer some explanation for the findings: The initrd of TC 2.9 contains 255 block devices ('/dev/loop0' to '/dev/loop254'), all of them with permission 664 and ownership of 'root:root'. Their only difference (apart from their minor number) is their respective time stamp ('2009-04-18 16:34:50' for 0 to 31, '2009-09-20 20:24:23' for 32 to 79, and '2009-10-03 19:32:54' for 80 to 254).
It appears that during the boot process the kernel creates a new set of loop devices. If no 'max_loop' kernel parameter is specified the devices 0 to 79 are re-created with permission 660, ownership of 'root:staff' and the current time stamp. For TC 2.9 the 'isolinux.cfg' contains 'max_loop=256' as parameter, so the kernel would re-create all 255 nodes provided by the initrd and add one more. I guess the default value is a kernel compile time choice, and if one would like to change it a kernel rebuild would be required.
By the way, I don't think that these block devices will "cost" much memory at all.