My feeling is, to use the old Scottish expression, "Nae fysshe, nae fowle, nay gude redde herringe" -- it's not a full minis game, it's not a simple game, it has no context beyond the battles.
Okay, let's put cards on the table.
With the creation of 3.5, we have a minis game. Remove the roleplaying aspects and you have a set of miniatures rules, replete with morale rules, movement rates, and all the rest. You can just set minis on the table, use every single combat rule, and you have a table top battle. But the Mini Game undercuts this system by simplifying several of the points and adding in extra classes that make sense in a minis game, but not in a rpg situation.
On the other hand, the Mini Game is not as simple as, say, HeroClix or other straightforward fantasy mini games currently available. You need more than just the Miniatures Handbook to play the game fully -- you definitely need the PHB and realistically need the MM and DMG as well to get full use, rather than having a short set of rules included in the gamebox. This means that you need to be into D&D before you get into the Mini Game, rather than just picking minis.
No, I don't see a need for or a point to the Mini Game. For those of you who do enjoy it, I sincerely hope you will have a great time with it. OTOH, I actively dislike the miniaturization of the rpg and feel that if we want a D&D-inspired miniatures game we need simpler rules for the minis.