Yes I sort of realised that the conversion can be done in a parallel mode - but because of the architecture of the whole system, i.e. how the rest of software which connects to arduino does it, it would be very difficult if not impossible for me to program it so I decided to go the easy way - I have limited time resources and I'm lazy 
The server software works in a way that a single command or batch of commands sent to arduino via serial will return a value, and the server will wait for this value until it comes or until timeout.
If I were to add another 18X20 probe all I need to know is its address and I can set it in the server software through UI alone without coding or compiling anything. Add a Probe, set Name, Location, Type, Arduino address, configure a Command for it, which would be something like '1WirePin 12!readDS18B20Temp 284CBAB101000051!' and presto. Optionally you add a relay board driven by any of the remaining arduino pins, set an Action in the software, set its type to Temperature and its Location the same as the Probe you just added, its commands similar to the Probe commands, i.e. '"0"="offPin 24!"; "1"="onPin 24!";' and you are able to schedule temperature in a room via Schedule - still using UI configuration only.
My goal is to be able to offer this software to the public and for this I want to have something which can be configured via UI alone.
I added a rough sketch of the architecture to the blog yesterday: http://chattyhome.com/blog/Chattyhome_blog/Technology.html