Since Windows 10 is looming on the horizon (next couple of weeks, I think), I thought I'd put this question out. If it's an obvious answer, feel free to Gibbs-slap the back of my head. 
Will HL work on Win10 without any major hassle or issue, or should it be pretty seamless in migration?

Will HL work on Win10 without any major hassle or issue, or should it be pretty seamless in migration?