I absolutely believe that it can.
I've got a Mid 2007 iMac that was purchased in August of 2007. It was the base model 20" iMac. That means it has a 2.0GHz Core 2 Duo, 128MB ATI 2400XT, came with 2GB of RAM (has 4GB now), 250GB HDD (120GB SSD now), and came with OS X Tiger preinstalled. I'm currently using Mavericks and El Capitan DP. It runs Logic Pro X, the Adobe Creative suite (PS, AI, LR, etc.), Office 2011 and 2016 preview, iTunes, Chrome/Safari/Firefox, Parallels, and more without a hitch since I put an SSD in it in 2012.
As mentioned, if your usage stays the same it'll be fine. I made my Late 2008 13" MacBook last till the middle of last year when I got my 13" rMBP and I expect it to last equally as long. The 2008 is still going strong for my brother and his family.
I think a new 15" will last because: everything is fully 64-bit now, the SSD out paces older HDDs in speed and reliability, it ships with 16GB of RAM which is more than enough right now, so it should work in 8 years even if it's the new minimum unlike my iMac that had 1GB, configured to 2GB at checkout and 4GB years later, and they are built better than the older ones as far as the cooling system goes and much more efficient. If anything it would need a battery replacement down the line.