Although i'd like to be proven wrong, i doubt we will see another Instrumental from Maiden.
As far as Adrian's contribution goes, he has usually only ever contributed to say 2-3 songs per album anyways. But it seemed to me that his contributions on BNW were just bits & pieces as opposed to whole song ideas. Perhaps now after 2 tours and a studio album under his belt, he feels more part of the band again and will come in with a couple of more complete songs....( a repeat of his form on SIT would be sweet). But in the 80's he & Bruce seemed to gravitate toward each other as song writers, and they did some brilliant stuff together. Now with Janick around, Bruce seems to write more with Jan as opposed to H.
Anyways, if they can simply capitalise on their revamped sound in BNW, push it a bit further, make the 3 guitars more of a feature, go for a heavier direction...i'll be happy. BUT who knows what we are going to get???
I hope that we get to see/read snippets of how things progress in the studio while they are recording. Kind of like Metallica are doing, i think that is really cool that they have pics and updates on whats happening....its great for the fans, and builds up some nice excitement, as long as they dont give too much away i think it would work well.