full digital distro would be the worst possible blow to console piracy I can imagine
As it turns out, nope, digital distro-only stuff on consoles is just as piracy-proof as anything else - which is to say, not at all. It's possible to run pirated download-only games on every current system except the DSi, and that's probably due to a lack of interest as much as anything else.
Summary of the recent situation for Sony's systems: no one bothered with the PS3 until Sony put out the slim without Linux, so no one found out for a long time that Sony screwed up big-time with the PS3's security (and by association that of Blu-Ray and the PSP). Hackers found the root keys for the PS3 and PSP, so it's now possible to sign homebrew (making it possible to run it on official firmware), and Sony can't permanently fix anything without issuing new hardware. A lot of this is explained a lot better in the fail0verflow
presentation from last month. (Also, Sony took the hackers to court over all this. I'm guessing the judge will decide it falls under the ruling from the iPhone jailbreak case that Apple lost and throw it out.)
For piracy, on the console side it means the USB exploit that made the rounds a few months back is obsolete, and on the handheld side, people with later PSP models can now play the majority of games available on that system, no mods or exploits required. Notably, this includes the PSPgo; owners of that system can now play non-PSN
games. On both systems, pirated PSN games work just like anything else, though the DRM used on paid DLC hasn't been cracked yet (one has to wonder why they don't just use that for everything).
I don't know anything about 360 piracy except that if you do it you're going to get your system banned from LIVE, and I believe several people on this forum have the Homebrew Channel installed on their Wiis (I don't) and could say more about that than I could. At any rate, it's possible to run pirated download-only games on those systems as well.
I'm not going to pretend to know what kind of anti-piracy solutions will be implemented with future platforms, but I'd guess piracy isn't going to be stopped even with full digital distribution. You can look at the all-digital system we have now to see that; even without the signing thing, people had already found exploits to enable homebrew (and by association piracy) using
demos.