Most jobs run on

<assignedNode>RHEL_any&amp;&amp;!RHEL4-ia64</assignedNode>
  or
<assignedNode>RHEL5_any</assignedNode>

However, a few are still tied to either RHEL5_x86, RHEL5_x86_64, RHEL4_x86 or RHEL4_x86_64.

And there's a new group of 5 slaves under RHEL6_x86_64 on which we could be building.

TODO:

1. fix jobs' assignedNodes

2. assign nodes to better labels (for example, there's no RHEL6_any and I don't know if the 5 slaves in RHEL6_x86_64 are also included in RHEL_any).