NP. I should mention we implemented this exact scenario with HA/DR and SUSE automated IP-based failover at 6TB scale. It works very well.
The HA is automated and the DR is manual - that's a deliberate choice and most customers won't want to automatically initiate the DR process.
HA takes a littler longer in SPS09 than I would like - around 2 minutes. The enhancement list on SPS10 suggests that this is faster now - they improved the row store takeover mechanism.