I'm re-doing a small company's IP scheme / netdesign for their LAN. They are growing fast, with many branch offices opening soon.
It's a mostly flat 192.168.1.x/24-ish out-of-the-box network. There is only one printer, one internal server, and most storage at a hosting company. Normally, I would pick an obscure part of 172 to avoid VPN problems, overlapping networks, tricky routing, overall security, etc. This is one of those 'Planning for growth' things - just like running dual Cat6/5e to all the desks, and separate electrical circuits where possible.
However, due to the rise in cloud computing and offsite DCs, as time progresses, I do not forsee ever serving much from this network, or more servers living here (beyond the odd VPN appliance or WAN accelerator). Number crunching will be done by virtual machines, on data that is hosted/stored on other virtual machines. Site-to-Sites become less useful with central hosted storage.
This is mind, what, if any, concerns might completely hosted company have ? VoIP gets its own separate WAN link, switching & wiring, and devices, with PBXs at a DC as well.
Is the network engineer outside of the DC really necessary anymore ;)