Why must they do this? (supposed HD that might as well be upconverted SD)

[takearushfan]

Hey all,
Wow. It's been years since I posted on here. Anyway...
Since Paramount/Warner haven't yet released a Blu-ray of April Fool's Day, I opted for the 1080p "HD" version from iTunes.
The first thing to hint that I might be disappointed was this seeing that a 1080p, 90 minute flick with two audio tracks (one being a 5.1), had around a mere 3000 bitrate.
I noticed that, despite being rescanned for HD, this is hardly more impressive than the SD upconverted. Further compression made it even worse. It looks like all they did was rescan for 1080p without ANY restoration of any kind, which is what I hope the Blu-ray will have done... if they ever get off their butts. But I digress
Any way to use Avisynth or anything else to remove some of this ugliness so it looks more like what a truly treated Blu-ray would? I know, you can't do much but I'd think SOME things could be improved. An untouched clip is attached. There's heavy macroblacking, random specks, some dirt and blur, as the tip of the iceberg.
I wish iTunes sources like these (while waiting for a GENUINELY touched up BD) would do at least a TAD more than this half-arsed stuff.
Any tips for some improvement is appreciated. Major deblocking, sharpening and speck removal isn't an easy one to tackle, it seems.
Thanks,
tarf