The OEMs don't support the old phones. That's why the OG Droid didn't get past Froyo. The phone's popularity doesn't make the OEM money if it's not being sold anymore. The Droid X may be popular, but it's no longer sold. Motorola (as a business, I don't agree with this) has no reason to support it anymore. Its main concern is the Droid X2 for the DX line. Don't get me wrong, I'd love to be proven wrong and get ICS, but I don't see it happening.
I don't think the Ally will get ICS either. It's an old phone, and if it hasn't gotten Gingerbread by now, I don't think it will. OEMs have moved on from these phones.