Horrible load factor

[JD]

Hi All,
on Ubuntu 12.10, I clicked on Ubuntu Software Center
in the apps menu bar on the left, and all of a sudden
I could get almost no response from the system.
I was finally able to run top in a terminal, and these
are the worst cpu hogging processes:

top - 14:54:48 up  2:14,  3 users,  load average: 5.35, 3.17, 2.26
Tasks: 238 total,  10 running, 228 sleeping, 0 stopped,   0 zombie
%Cpu(s): 73.4 us, 26.6 sy,  0.0 ni,  0.0 id, 0.0 wa,  0.0 hi,  0.0 si,  
0.0 st
KiB Mem:   2065284 total,  1757384 used, 307900 free,    58944 buffers
KiB Swap: 12586916 total,     9172 used, 12577744 free,   413636 cached

   PID USER      PR  NI  VIRT  RES  SHR S  %CPU %MEM    TIME+  COMMAND
  1221 root      20   0 85684  35m 9244 R 39.4  1.8  21:25.33 Xorg
  7559 jd        20   0  531m 151m  36m R 13.5  7.5   4:37.02 thunderbird
  8805 jd        20   0 65084  37m  24m R 13.5  1.9   0:06.17 
update-software
  3694 jd        20   0  688m 182m  34m R 13.1  9.1  22:17.12 firefox
  8725 jd        20   0  270m  84m  36m R 9.9  4.2   0:16.87 
software-center
  2056 jd        20   0  232m  76m  31m R 4.9  3.8   4:51.45 compiz


This is very very bad for a unicore AMD64 3700+  cpu.

Since I just installed 12.10, is this a clear sign of what to expect
using ubuntu?