There's more work to do on DoS, but I'm doing a quick build of what I have so far in case it's needed, before venturing into more complex ideas.  The build for this is version 0.3.19.

- Added some DoS controls
As Gavin and I have said clearly before, the software is not at all resistant to DoS attack.  This is one improvement, but there are still more ways to attack than I can count.  

I'm leaving the -limitfreerelay part as a switch for now and it's there if you need it.

- Removed "safe mode" alerts
"safe mode" alerts was a temporary measure after the 0.3.9 overflow bug.  We can say all we want that users can just run with "-disablesafemode", but it's better just not to have it for the sake of appearances.  It was never intended as a long term feature.  Safe mode can still be triggered by seeing a longer (greater total PoW) invalid block chain.

Builds:
http://sourceforge.net/projects/bitcoin/files/Bitcoin/bitcoin-0.3.19/

I thought the idea of safe mode was to protect sites like MtGox from losing everyone's entire balances in the event of a catastrophic exploit. Safe mode shuts down their transaction processing until they can work out what's going on, and upgrade/patch if necessary.

For the sake of appearances, it's better not to have safe mode turned on by default (because "remote tampering" of one's software is not popular with many people). But why not have safe mode disabled by default, and provide an "-enablesafemode" switch for those who want it?

Previous discussion was here:
Development of alert system
and here:
Version 0.3.11 with upgrade alerts