We already do CDN-like stuff with our public gateway system.
Geo-based DNS resolution points you to the closest gateway.
You can use IPFS Cluster to easily distribute content to all the peers serving your gateways too.
Finally, I’m not sure if IPFS bitswap includes any optimizations to fetch content from the closest peers (in terms of network latency), but otherwise it’s surely something that will arrive sooner or later.