OK, ignore my previous endorsements of eMusic. From a message titled "important subscriber information" they just posted:

As of November 8, EMusic will be discontinuing the unlimited service offering and replacing it with a new service offering that places a reasonable limit on the number of downloads available to each subscriber in a billing month.

At that time, EMusic will offer two service plans:

EMusic Basic: $9.99 per month/maximum 40 downloads
EMusic Plus: $14.99 per month/maximum 65 downloads

I guess I will be downloading everything I can from eMusic between now and then and then promptly cancelling my subscription in favor of the iTunes music store, which has much better selection ...