I'm a complete sucker for piano songs so I adore Silence and Lightsleeper and would welcome more of the same. That being said, I will follow Neil's musical path where it shall lead. Sounds like he'll be playing guitar and not piano with Fleetwood Mac so perhaps more guitar driven songs will be down the road. If Christine leaves the band, I could see Neil taking over keyboards for her and Sheryl Crow playing rhythm guitar as I believe that's her preferred instrument.
The other thing I thought of was that Neil discussed in a recent interview that he has always written songs on piano but he used to transfer most of them to guitar for Split Enz and Crowded House. Nowadays he simply keeps them on piano for the final product.