I haven't noticed; PC has been acting entirely normal for me. What exactly is happening slowly for you and what do your status messages, etc., say while it is?
If other sites besides PC are involved I'd wonder about...
- your connection
- your browser
- your operating system
- your computer
- maybe even your part of the Internet.
How you'd check (1.) depends on how you connect -- dialup, DSL, cable, satellite, etc. I'm only familiar with dialup.
When I'm in doubt about (2.), (3.), and (4.) I try shutting down and rebooting. If things still seemed slow I might try sweeping for viruses and spyware, then finding and disabling any unnecessary programs that might be running in the background for my supposed convenience.
Ten years ago we could use programs like NetMedic or TRACERT to find possible bottlenecks (5.) along the Internet. As far as I know, though, servers have been reconfigured since then to no longer respond with the relevant information.
Any changes since you posted?