The GRP recording mentioned by Allan is an enjoyable recording, but be aware that it is recorded in 5.1 channel DTS. I am not aware of other recent/new recordings of Glen Miller material, but you might check out the recordings under Tex Beneke's name. Beneke "inherited" Glen Miller's orchestra, and did a few "modern" recordings that may be available on CD. Here's a link to Tower Records that has Beneke/Miller Orchestra recordings:
http://music.towerrecords.com/[email protected]&sid=45673F244432
http://music.towerrecords.com/[email protected]&sid=45673F244432