Pretty sure there will be full frontal, at least, of course, if we have the gameplay trailer to go by, as it had to blur out the bits... both places. I guess it could be ken and barbie, but then again, if that were the case, why blur it at all? It's not nudity. They also stated that nudity has a clear connection to the presentation of the game, as it's a world with heavy body modification and is meant to be, in the game, a serious implication and determines how people react to you.
When it comes to sex, it should be tasteful. Witcher 3 as an example, I thought the Triss/Yennefer, and girls of lesser repute, to be well done, though I thought the Shani scene was funny, as they included boob licking (just imagining the person animating that...). Penetration is obviously out, imo. Modders will do that, so there's no need for CDPR to limit their audience in such a serious way, especially if they want it to be successful (like it or not, not everyone is ok with that, further debate is unnecessary). Doesn't mean they can't do something that paints a nice picture of love between two characters, or the hedonist out for a good time in as many ways (and with as many people) as possible.