This is just a redo of Napster's much-derided "Do the math" campaign from a few years ago.
Yes, you get a lot of music available to you for a reasonable amount of money per month, but when Zune goes down (and it will) you lose access to the music you subscribed to (as opposed to buying outright a lifetime-license). Given that even the MSN Music store went down after about 4-5 years that's $14.99 * 12 * 5 = nearly a thousand dollars, gone.
Also, the advert is wrong about it costing $30,000 to fill an iPod, reasons include:
- People ripping their CDs and putting that music onto an iPod (and old CDs go for about £4 or even less in bargain bins)
- People using their iPod as a Mass Storage device
- People using *gasp!* free music
- and of course, bittorrent

Also, the Zune pass limits you to 3 Zunes and 3 PCs. I've got 4 PCs I use regularly (home desktop, laptop, halls desktop, and terminal server), I guess I'm stuck then.
John Gruber had a good take on this back in 2005 when it was Napster doing it.