It seems the server is identifying it's IP address as 0.0.0.0 now (obviously the address used to bind to all address - last fix).
This results in clients failing to connect.
Related issues
duplicates
Comments

I suggested three changes in a comment on #MC-473; it appears that (1) has been done, but (2) and (3) have not.
The two remaining changes are:
2) when announcing our address to the network, if listening on 0.0.0.0, replace it with (an attempt to find) our IP address in the 'AD' packet (optional; only needed if you want to remain compatible with versions < 1.4.4)
and more importantly
3) when parsing an 'AD' packet, ignore the IP address in the packet, and replace it with the address from which the packet was received
If Minecraft was open source (or not obfuscated) I'd have given you a complete patch 🙂 but as it is, a patch relative to the de-obfuscated source in MCP is the best I can do:
http://www.pseudorandom.co.uk/~smcv/minecraft-1.3.2-lan-server-v4.diff
(I had this working correctly as a mod for 1.3.2 / MCP 7.2; I can update it to 1.4.2 / MCP 7.19 if that would be useful, just ask.)
The change in what MCP calls LanServerList.func_77551_a is the important bit. I doubt those names match what Mojang calls that class and function internally, though.
CubeTheThird, happens on any network, tested on wifi managed, wifi adhoc and wired.
Simon's right, his 3rd point should fix this particular issue.
I'm not on Linux, but I'm getting this issue with Windows 7 Ult x64. Particularly the 0.0.0.0 when I open to LAN... it's frustrating 😞
1.4.4 on linux it's workse than before (1.4.2) now, as I could tweak /etc/hosts manually before, which is no longer possible when opening to 0.0.0.0.
Workaround: starting the world as a true SMP version.
The 1.4.5 prerelease seems to fix this in the way I suggested (part (3) only), and works for me (with two Linux machines, both upgraded). Please try again with that version.

So we can resolve this ticket as a duplicate of MC-2583 ?
What type of network are you using?