I was getting:
Not FoundThe requested URL /metalink/plsql/ml2_gui.startup was not found on this server.
Thinking that this may be due to Metalink Outage, I didn't bother. However when this occurred even on Monday, I cleared my cache and accessed metalink again. They have made the flash based Software Configuration Manager interface (available from Software Configuration Manager tab inside metalink) the primary choice. You also have the option of selecting the classic metalink. If you do not want to clear your cache, try this link which will give you the option for chosing software config mgr or classic metalink:
So now you have 3 metalinks:
https://metalink.oracle.com takes you to Software Configuration Manager interface
https://metalink2.oracle.com takes you to classic metalink
https://metalink3.oracle.com takes you to Metalink version 3 which is currently available only to Siebel customers.
The new metalink or "My Oracle Support" still gives this error regularly:
My Oracle Support Services Error
A server connection error occurred
Security Error #2048
Please try again later.
For now I am using the classic metalink interface, as it is faster. I'll experiment with the software configuration manager interface sometime later.