Personally, I don't mind giving out an email address in return for free software. It seems a fair exchange, especially since they are selling other software. It is unlikely that they will give your email address away but rather keep it for their own marketing.
I do find giving out email addresses more and more difficult because of spam. Having said that, because of the amount of spam I get, if they did send me any marketing material it is likely to get lost in my trash anyway.
ArtRage for Art | EnergyXT2 for Music | Blender for 3D