Secure communication between linked SQL Servers

There is no solution from SQL Server that allows for 'transparent' data access. Querying across many servers requires Distributed Queries (ie. linked servers) and having a solution deployed with hard coded queries against linked servers across many instances will quickly hit the ground, for reasons of availability and maintainability. Is surprising how mobile databases really are: server change names, failover happens, databases are moved for reasons of load balancing. Given the tight coupled nature of DQ this doesn't really work.

Other big deployments approached this by going SOA and relying on messaging, see MySpace Uses SQL Server Service Broker to Protect Integrity of 1 Petabyte of Data. This implies a serious paradigm shift in programming and how one approaches the solution, existing apps that use T-SQL queries will not magically transparently work on a 'farm' of servers.