I need a list of ALL the authorized Dell Service Providers in the
greater Houston, TX metropolitan area. I only need those service
providers that are "Tier 2 Service Providers" (eligible for labor
reimbursement on qualified incidents).

For what it's worth, I located
http://premieraccess.dell.com/us/program/CT000000.asp
in a Google search, and spent some time on the phone with their
contact person.
According to them, the Tier 2 program is built around Dell customers
who maintain at least 100 Dell machines, and involves certifying
someone to maintain those machines whose work Dell will reimburse
under warranty.

The person I spoke with at Dell was unwilling to disclose the names of
any of Dell's Tier 2 service providers.