Someone asked: What are your thoughts on MPLS?

"This appears to be the next generation of communications. There are numerous applications that can take advantage of this latest technology in being able to prioritize data packets by assigning labels to them. Of course, it's early days, so what are your thoughts?"

My reply:I would say that MPLS is the 'Now' (not the Next) Generation of backbone technology. In Europe and AsiaPAC it is already the technology of choice for most new WAN implementations and the number one service offering from most Global telco's, not to mention the main focus of Vendors.
I have been involved in MPLS WAN rollouts for 5 years now in the UK and Europe.
My only caution would be to not forget to compare the business cases for MPLS and competing legacy technologies when considering a change. Often the Service Providers push customers into MPLS because it is fashionable and the margins are better for them as they can bundle multiple services with it (Data and VOIP plus enhanced network monitoring tools etc). Whether MPLS 'costs in' for a customer will depend on (a) existing and future bandwidth requirements; (b) the need to flex bandwidth on demand; (c) geographical spread of WAN (distance from the exchange and regulatory restrictions).
I have had clients who have been halfway through the rollout of an MPLS WAN only to realise that they are going to spend more (not less) on a technology that they won't really benefit from. Also clients have ditched MPLS when they realised that they could double their existing ATM bandwidth cheaper and faster in some locations, rather than deploy MPLS.
Overall though, with (a) the refresh of network infrastructure now better built into operating budgets and (b) the realisation that things like VOIP and convergence of legacy and current data networks are no longer a leap of faith, as well as (c) the removal of premiums for MPLS services - it is truly becoming the default technology for todays Wide Area Networks.
British Telecom as well as all the other UK, European and US Telcos I can think of, all deploy MPLS as their carrier backbone technology. It is highly likely that if you buy ATM in some locations today it will be encapsulated over MPLS anyway!