I am currently using Delphi 2006 a few days ago I downloaded a copy of Delphi 2010.
How stable is Delphi 2010?
Should I wait until the first service pack comes out before moving to this version?
EDIT
I have been using Delphi 2010 for a few months and it is great.
The version of Rave reports (7.7BE) that comes with Delphi 2010 is full of bugs and has made migrating software from Delphi 2006 to Delphi 2010 a nightmare. Rave Reports 8.0BE has just as many bugs
In my opinion, it's very stable and usable. More so than even Delphi 2009, which I also like a lot.
I understand a lot of issues with Generics have been cleaned up, too.
Definitely ready for production use.
It seems to be more stable than D2009.
But in regards to your question, who can tell?
D2010 was released days ago. It will take at least a couple months to be confident that all major issues have been uncovered by Delphi users. Then you can judge whether any are show-stoppers for you. If your release timeline can't hold off that long, then plan on using both compilers for a little bit. The good news for you is that it's quite easy to write code which works in both.
I like Bruce's answer. Let me just add to what he said that debugger visualizers can make debugging a whole lot easier. Between visualizers and improved generics it's definitely worth upgrading from 2009. (The RTTI and Attributes can be helpful too, depending on your program.)
Using it for quite some time. More stable then 2009, 2007, 2005. I even have days without a single crash. I hope it will be weeks for the next D2011.