There is 1 line: 4th Edition. Essentials is a just a series of 4e products, just like the Player's Handbooks are a series of 4e products. The Red Box is one of the Essentials products.
One big, completely-confusing-to-new-players line. (And the incompatibility between the introductory Red Box and the rest of the Essentials line is, frankly, bizarre.)
MINIATURES
(1) If I had to draw one conclusion from the cancellation of the miniatures line, it would be that canceling the D&D Miniatures game had a very large, very negative effect on D&D miniature sales.
(2) I'm not sure if miniature design was done in-house or under contract. But whoever was doing it no longer has that job (or will lose it in the very near future). Slavicsek says their future miniature plans are limited to Collector's Sets and the boardgames: Both of those have used pre-existing sculpts and I suspect the same will be true for all future installments in those lines.
DDI
The decision to apparently further torpedo the value of DDI subscriptions on the heels of what many subscribers considered to be a reduction in the value of the DDI sufficient to cancel their subscriptions is a very strange choice.
If their intention is to radically increase the amount of DDI-exclusive material by shifting content from printed products to DDI content, then that may gain them some of that good-will back.
But even if that's the case, I'd be skeptical in the long-term. Without any guarantee of the amount of content they're providing for the subscription fee you're paying, the temptation will be near-constant to reduce costs by reducing the amount of content provided, the quality of that content, or both.
Given their track record, expect WotC's digital offerings to continue to flounder.
BOARDGAMES
I hope these continue to do well. First, because it's the only thing WotC is producing I have any interest in paying for. Second, because I think it's the most effective introductory product produced for D&D since TSR stopped publishing the original red box in 1991. (And, yes, that includes the dysfunctional new red box.)
With that being said, they need to fix the rulebooks so that the game can actually be played without needing to house rule 50% of the game.