it really depends on the pine in question... i wouldnt be heading down to your local B&Q for tonewood
parker have been making fly's from spruce for quite a while... and obviously almost evey acoustic in existence has a spruce top. ( infact i worry about alll you peeps gassing after ibanezes acoustics with pretty hardwood tops, mahogany just about works but it really needs to be a softwood for an acoustic top)
spruce is a great tone wood, its a little soft to hold a screw well for an electric guitar bridge (see the yamaha RGX for a way round that) and it dents really easily... and dare i say... most people would find it too light as a solid body electric.... but it is a softwood..... so is redwood which is also used in guitars more and more of late... both these woods make great electric guitars
douglas fir is another softwood which might work for electric guitars.. i know melvyn hisc--k (the writer of the bible) has been experimenting with it, even for necks
so pine,,, yeah, why the hell not... but it still has to have good grain structure to work with... i would be looking for at least 10-15 grain lines per inch rather than the 1-2 you see on the sponge you can buy from the average diy shop, and it would need to be really dry and stable (unlike teh sponge you buy from the diy shop). antique pine can be great because it generaly comes from older trees which means straighter grain, less knots and its more likely to be dry... works better with lower powered pickups for something very acoustic sounding as well