The main problems is high motion scenes and also low fps sources 24p,25p, 30p.
Most of them have high motion burr, so instead of hard edges between some elements there are blurred areas. In these places quality suffers a lot- there are big artefacts.

I don't know if phase plane correlation can help, but it's used in other high-end solutions.

As I understand this is improvement of the usual search of blocks motion vectors. First, a MV for each block is calculated, and then, each vector is corrected considering vectors of neighboring blocks. It should help at getting rid of artifacts on regular structures.

Насколько я понял это улучшение обычного алгоритма поиска MV блоков. Сначала выполняется обычный поиск векторов для каждого блока, а потом каждый вектор корректируется, учитывая вектора соседних блоков. Помогает бороться с артефактами на периодических текстурах. В качестве примера там берется дом с окнами.
Картинки из pdfки (слева результат их алгоритма, справа - обычного):

faster processing
We have such plans to future.

8bit+ support or at least 4:2:2
We will think about it. All this time we worked on enchancing 8bit YV12 processing.

Is phase plane correlation a "better" solution for engine?
Sorry. I don't understand.

Is there any update coming soon?
Yes. It will be bug fix release with some new stuff for smoothing stereo and better quality on Intel HD4000 graphics. Of course including of components updates.

Well- I'm mainly after better engine quality, faster processing, maybe 8bit+ support or at least 4:2:2, ....
Is phase plane correlation a "better" solution for engine?

Is there any update coming soon?

yep, in Russian 

but you're free to post any good ideas for future releases here

Is SVP still being developed?
Is there any development list/ideas?

Thanks,
Andy