"We are hard at work upgrading all of the SL infrastructure"

[Selc]

"We are hard at work upgrading all of the SL infrastructure"

What does this mean? Sims will be cheaper & have less latency issues?

"make SL more performant"

What does this mean? Higher frames per second for everyone?

[Bobbie Faulds]

FPS is dependent on you...ie your graphics card and connection. 

Though it sounds counterintuitive, check your speed. I keep mine at 800. Higher isn't necessarily faster. Think of a hose. You connect it to a spigot. Bigger will usually give a slower flow. If you use a smaller hose, you get a more forceful spray. Same thing applies to the data speed.

[Innula Zenovka]

I would think it probably means they hope regions will run better and crash less frequently.   I would think, too, that they hope to make communications with the inventory and log-in servers more reliable,  and also improved the stability of various off-world features, like the Marketplace, billing, customer support and these forums. 

As Bobbie says, your FPS has, most of the time, little to do with LL.  So much depends on your computer your settings, your connection, and conditions on the individual region, which are all outside LL's control.