Kun engelsk ...
What's new is another recuring session you have to go to. You could also just go to http://esri.com/software/arcgis/arcgisserver/whats_new.html.
Ismail Chivite and Anne Reuland led us through the new stuff starting out with the ESRI mantra 'Author, Serve, Use'. Ismail then went on with the core GIS services stressin out that there has come a lot more server objects to play with; Image server for example. He then continued with Map caching where dynamic caching and caching on demand is the two new players. Dynamic caching means that you can choose not let all zoom level be cached. Imagine if you only show given point symbols i given zoom level and only some are updated frequently you can now let these be non-cached in order to stay updated. Caching on demands means that you can publish a chched map without having any caching yet. This is not recommended however. Instead you will draw a polygon telling server to update only tiles within this. And while we are at it: remember to choose your tiling scheme so it will mix well with used base maps.
Image services have properties so you can play around with colors. Adjust the transparency and mess around with alfa channels. You also have a orthorectification tool available.
Since 9.2 the documentation has grown extensibly. You should read it!
Interoperability is another corner stone in ArcGIS Server. Among the many supported formats are WMS 1.3.0 with SLD (Styled Layer Descriptors) and KML 2.0.
Then there is the services directory where you can see what's availble. These are web pages which are searchable on say Google.
Server administration has improved. It is now possible to log in without having amin rights on the server. Also security has been addressed in 9.3.
Last topic was web applications. The web ADF has been improved: lighter, faster, and with more tools. For example there is a new Print task available. The map extent can now be set in the manager thereby overruling the extent in the map document. Finally it was told that the mobil apps have improved and just to mention one improvement is the possibility for partially connected mode. Get data and go offline. Edit data and sumbut changes the next time you are online. Think Outlook. Flex and the JS api wer mentioned by only briefly discussed.