Ideally, you'd want to pipe SACD and DVD-A streams digitally into your AVM-30 and have it do all the processing and then a one-time D/A conversion. Even if a hi-rez digital interface did show up today for your processor, you'd still have to convert SACD signals to PCM because your processor doesn't have A/D converters for DSD signals. But since you don't have a digital connection for hi-rez audio, you have to deal with the analog signal from your player. This means you have to compromise somewhere.
You can leave the signal in the analog domain and simply send it to your amps, whereby your AVM-30 becomes a multi-channel volume control. The bass management and time alignment of the signal would be done in the player, and you would maintain the full resolution of the original signal. That's the upside. The downside is that players usually don't have the flexibility of pre-pros, even when it comes to things like bass management and time alignment.
If I were in your situation, I'd use the AVM-30 to re-digitize the incoming analog signals; which is what Meridian, Lexicon and Mark Levinson processors do. The downside is that no A/D-D/A conversion is 100% transparent. The question is: how much degredation will you hear, if any at all. Since you already have the AVM-30, try listening to a 2-channel source in Analog Bypass and then via your processor's A/D-D/A. If the difference is negligible enough for you to live with, then the upside is significant because having the signal in the digital domain has lots of advantages. Follow:
Having the signal in the digital domain will allow you use the AVM-30's bass management and time alignment features, which are quite good. Further, these settings will remain consistent for ALL sources; i.e., you won't have Anthem bass management & time alignment for DD, DTS and PCM sources while having Denon's bass management & time aligment for SACD and DVD-A. Since your speakers aren't going to change from source to source, there's no reason your bass management and time alignment should. Dial in the AVM-30's bass management based on the capabilities of your speakers, and you're done. Besides, you're not going to find the Anthem's subwoofer polarity and phase control on the Denon player.
Unless you have some reason to be a slave to the delivery format (2-channel sources = 2 speakers, 5.1-channel sources = 5.1 speakers, etc), you'll find it handy to have the option to use surround processing. I don't know if you've tried Anthem Logic or PLII music modes, but both do a good job of extracting ambience from in front of you and placing it around you (as you would hear it when you listen to live music). Anthem Logic is the more passive (and subtle) of the two processes, though PLII can be adjusted to suit your personal tastes. In my experience, both sound better than having your room supply the spacial/ambience cues.
Speaking of your room: converting incoming analog signals to digital will allow you to take advantage of any room correction/EQ capabilities that Anthem currently has and may provide down the line. Having heard room correction on Meridian and Lexicon processors, I found them to be very useful. The main thing they did was minimize the room's interference, thereby allowing you to hear more of the sound of the speakers and source material. This is more noticeable on well recorded live music; the less you hear of your listening space, the more you'll hear (and appreciate) the recording space in the source material. Even something as simple as the AVM-30's notch filter can be extremely usefull in killing a room resonance that would normally obscure the clarity of the music. The Denon player doesn't have anything close to that.
You've got an excellent pre-pro, with features that can really help you get the best out of music recordings. It's up to you whether you want to take advantages of those features or use the pre-pro as a multi-channel volume control. It depends on what's more important to you: the recording or the music.