@Joseph,
When you say "the Glossary Block", I suppose you mean the "Random Glossary Entry block". The "Next Entry" order option has been carried on from Moodle 1.9 to Moodle 2 without any change or improvement.
It would be extremely easy to add an "alphabetical order" display option to that block. I have created bug report MDL-35842 with the necessary patches, for which you may vote.
Joseph