Yeah. ARDRs are mining tokens. You can mine blocks with them and earn the fees of the child chain transactions in the block. A nice dividend. And you can send ARDRs from account to account. That's pretty much all you can do with ARDR tokens. All the additional functionality of the platform like Asset Exchange, Coin Shuffling, Message System etc. will only be possible on the child chains. As a NXT holder you will get the first child chain token with a ratio of 1:0,5. But the snapshot for this second distribution will be at launch of ARDR mainnet in Q3 2017. So you should keep your NXT after the first snapshot of October 2015 to be eligible for the child chain token later. Or rebuy before the second snapshot. This solution should also prevent an exaggerated selloff of NXT after the first snapshot period.