I've am currently experiencing this problem too.
I've tried several times and changed a few things alas still no Mavericks.
First attempt instal halted at "About a second remaining" for over an hour. I did a hard reset and tried exactly the same again - no luck.
Second attempt I re-installed the USB drive with Mavericks, erased the hard drive and tried again - halted at "About a second remaining" for over an hour.
Third attempt same as above and now halted at "About a second remaining" for the past hour and a half ... could anyone reasure me that this install taking well over 2 hours is normal as most are only experiencing problems for 10-15 mins ...
Thanks in Advance!