Really? Because you don't like the aesthetics? Well, I for one like the new iCal.
It's mostly faux-design sense (everybody is a snobish designer these days and everybody is for "minimalism") than anything really problematic with an app that has some faux-leather as its background.
Everyone isn't moving towards "minimal" designs because they're a bunch of me-too-tools. They're moving towards minimalistic designs because that is the most pragmatic approach. In a world where apps have to routinely launch on 3 very different platforms; in a world where we are artificially constrained in even our minimal layout capabilities by old browsers; in a world where page size is becoming a premium again, skeuomorphism has an increasing cost.
And while graphic designers love it, UX designers often find the expectations raised by the metaphor conflict with the actual implementation. A great example of this is book apps, in which the notion of "pages" and "bookmarking" is presented in a familiar visual style, but the actual experience is radically different.
Thankfully they've fixed this in Mountain Lion, but the "page turning" effect in the Lion version of iCal was for me an example of infuriatingly poor design. Want to scoot ahead eight months? Please wait one second between each month while we execute this fancy page turning animation!
It's design decisions like this, which really ramped up in Lion, that I think are fueling the present-day reaction against skeumorphism.
Indeed, pagination us a particularly irritating decision. We get all the penalties (non-infinite view, poor visual seek, discrete scrolling) with none of the benefits (bulk age turn, navigate by physical feature, detachability).
The calendar app is a work of supreme laziness on the part of its designers, and the excuse seems to be that it is pandering to a class of user both looked down upon and considered unlikely to actually use the app.
It's mostly faux-design sense (everybody is a snobish designer these days and everybody is for "minimalism") than anything really problematic with an app that has some faux-leather as its background.