A strong second on that recommendation to hold out till 2008.
My only disagreement with anything Steve wrote is regarding the stability of SQL Server 2005. Yes, the data engine of 2005 is surely stable, but the development integration -- where they seemed to focus -- is less reliable than it should be given the beta cycles they went through. The best example of this is the horrendous management tool interfaces, which on many development boxes were seriously hamstrung. And requiring a development tool upgrade to VS 2005 just to get at some features was a problem in terms of deployment, since VS 2005 was not backward compatible. It produced an added layer of swkward management, and that affecte dproductivity.
I'm not saying SQL Server 2005 was a bad release, though, just that when you analyse their development process, beta cycles, and so forth, it just wasn't really a solid release. The same is true of VS 2005, which wasn't really usable in many scenarios until SP1.
My biggest fear for 2008 is that a trio of upgrades will create a slew of isolated platform bugs, and an unpleasant batch of integration-bugs. MS needs to consider slowing down and committing to point releases and optimisation for a few years after 2008, or it will cut their bottom line.
Well,Nobody talked here about the costs.This is another reason for companies not upgrading now to another SQL release.
But anyway,i believe there's also a need to keep the technological wakefulness so,not migrating to SQL2K5 might also be a problem if you do not have an efficient test environment.
The hen and egg issue?
We have only one SQL 2005 install here and about 20 servers on 2000. I have been disappointed in several bugs or things broken by SP1 and SP2 and some of the Ent. manager ease of use things for daily DBA tasks are gone or horribly rewritten in Mgt Studio. Mgt. Studio is TOO SLOW. I am very disappointed on how difficult it is to simply set up a job to bring data into a SQL Server table from another RDBMS. DTS was not the greatest but it was simple to use.
We are in a budget crunch here and I cannot goto Management and ask for $250,000k + to upgrade all of our SQL Servers to 2005 and then say oh, next March there will be a new version and we have to rebuy SQL Server all over again.
Well, I think it is horses for courses. And I get the impressions Steve does intend that as well. Some of the new things in SQL 2005, however, may mean you don't want to wait (.. or didn't wait, as in our case - we've been on SQL 2005 since... 2005). That said, we also have several SQL 2000 servers, and some 7's as well. Upgrade where you need to, for good reasons, is my opinion.
Some of the performance and stability issues we (by we, I mean our core client) had was around a massive caching system that aggregates and presents data from several hundred SQL servers, and then makes this available to our customers (somewhere in the order of 500 million to 750 million 'tuples'). Towards the 2nd half of 2006, the SQL 2000 DB cluster had frequent problems - to the level that the cluster was failed over on a near-daily basis. Now I am sure many people will think that this is due to bad code, I should point out that what was done here was reviewed by MS, and was considered by Ms as a very good, innovative solution to a very challenging problem. After upgrading from SQL2000 to SQL2005 (with virtually no code changes), this server now runs at an average CPU of around 10% and has not needed a fail-over in 9 months.
Not everyone will have these needs, but the performance improvement can be significant, as can the 24x7 enhancements.
I should also say that SQL 2005 is not the panacaea for all SQL problem, either. In some areas, I'm not sure it is that stable a product - SQL 2005 SP2 and SP2a debacle a prime candidate. We still have assertion errors on 1 of our (5) live SQL 2005 server clusters, and have had them for 2 weeks now... we are on build 3175 with no resolution. Fortunately, is doesn't appear to have an impact (yet) on our service, but it is very concernign to see 80-100 assertion errors a day, on a server.
Hmmm .. I'm not sure I agree, the biggest advantage of sql2005 is 64bit and I'd hope we were all heading this way very quickly - I accept I tend to work in large companies who benefit from such advances.
There's just so many advantages with sql2005, security, tuning, analysis - waiting until sql 2008 would likely mean another 18-24 months, as I'm sure most would wait for sp1 before an upgrade ??? , by then you'll be running on 9 year old technology.