Upstream Nouveau was unaware of this issue that was affecting my entire assortment of NVIDIA GeForce hardware so it was then quickly assumed to be an issue with the Oibaf PPA that constantly is packaging the latest open-source Linux GPU drivers. On top of mainline Mesa Git, recently there's been the the Gallium3D Direct3D 9 patches (Gallium-Nine). While none of my testing was relying upon the Gallium-Nine D3D9 support, it was wreaking havoc on the system anyhow.
As of earlier today some patches were backed out of the Oibaf PPA and since getting back closer to Mesa mainline the Nouveau problems are a matter of the past. With that said, now I'm in the process of running some Nouveau Steam/Source Engine Linux gaming tests similar to today's 20-Way Radeon Comparison With Open-Source Graphics For Steam On Linux Gaming.