I like the idea of these rules. It creates a mini game where strategy trumps role-playing, for a short term activity within a campaign.
I like the idea of making solos as important as an entire stand. It's a reprensentation of the solo's efficiency and importance in battles. It's fun to consider a solo as capable of eliminating an entire group of combatants, heroic deeds! If it irks your sense of realism, you could maybe consider having stands represent different numbers of creatures, for example a stand of magic-users could comprise 2, 3 or 4 creatures instead of 10. If the creature is so important such that you want it to be on equal footing with a solo, then... make it a solo

But I believe stands are meant to represent groups of grunts.
[MENTION=6684404]Superchunk77[/MENTION] I have not seen reference to a battle between solos reverting to 6 second rounds. This was in a previous article by Mearls when he had first intruduced this concept some months ago, but apparently it's been dropped in this version of the mass battle rules. Personally, I'm pretty happy with that as I didn't want to see a solo vs solo fight in-between rounds of the mass battle.
I'd like to be able to test these rules in the near future. Hopefully I get a chance to try them out, as I'll be DMing a campaign where mass battles would exist. I'd love to see they come into play. For now, it's tough to see how the strategy of identifying skirmishers vs regiments, how making bigger units or more smaller ones, how to improve stands with solos/commanders, and this kind of stuff, will influence play. Looking forward to seeing how it plays out.