Thanks for the heads up on Dabble DB. Hadn't heard of it before but judging from the demo video, I don't see much concerning the calculation engine. It seems more like a visualization tool for relational data.

Aabel seems particularly oriented towards graphing series of data points but it's hard for me to tell from their site how close it is to multi-d spreadsheets.

As for Apple adding it in the future, I don't think that would work. The paradigms are different enough yet they look superficially the same enough that having both in the same product would spell mass confusion. As scary as the whole multi-d thing sounds, when actually learning it as a total novice, I believe it to be more intuitive than the traditional model with the important caveat that the user has never been exposed to a spreadsheet before. I'm throwing out all this wordy analysis and the paradigm has been worked out rigorously to where it's almost like it's own math but users don't have to know any of that to use it. The problem is that once they pick up the Excel/traditional way, moving to multi-d is much, much harder.

Basically, we have the odd situation of a product that works for both complete novices and hardcore users, but not the people in the middle. The current products shoot for the upper part since history has shown that there is uptake there. Question remains whether the product can be marketed towards the novice users but for now it seems that Apple is shooting for that creamy middle.