I haven't *really* gone the smartphone or tablet way yet. At home it's the PC for photography, I don't play games myself, for most things I would be satisfied with a laptop - the keyb is very important for typing in MS Office and Outlook email. My phone is only a 3" which gets the job done when I am outside, that email or that GPS.
I don't have a tablet b/c at home there is the laptop, if I didn't have a laptop I may get a tablet to lounge with if we travel overseas can use it. NZ hasn't really taken off with 3G or 4G, so while I may get a newer Smartphone just for Google Maps b/c some countries that I visit are not on Nokia Maps you cannot really use the potential. Like if you're on travel in NZ, it's cost prohibitive as people like to do - stream videos, Skype chat to do things as they would when they are at home. Mobile calling have gotten a lot cheaper these days my first mobile phone was $2 per minute for NZ dialling. With calling you can use it without much hesitation, unlike data.
I use my Desktop a lot, Very rarely use my Laptop, I much prefer the 2 screens, Use my phone a little when I absolutely must but still prefer the Desktop, Might get a Tablet one day, When I decide my phone is no longer good enough for browsing the internet on the toilet.
Laptops seem archaic after getting used to my win8 tablet, it's only atom powered so not a complete replacement more like only a 98% solution but i will upgrade to the next generation of Intel tablets once they get atom levels of battery life with i5/i7 levels of power. At that point i guess the desktop is dead and obsolete for the majority of consumers