Thougths about Sharepoint backup recovery solutions

• SQL mirroring is a good solution but provides only database availability, the farm's Web Front End's should be planned seperately.It is possible and very easy to backup the web servers by the help of virtualized environment but if there is no virtual solution available then a load balanced method could be used.

• The real problem is backing up custom applications that are developed using Sharepoint Object model and working on Sharepoint. since the programmer deploys them and places the dll and other code files under the wfe accordingly, i am really not sure if there is a way other than backing up them manually. My solution here is, 
• request  an installation/deployment document from the developers for each web part/solution/feature/web application in SharePoint; 
• test the documents in a test platform, make sure that they are working ; backup all the files/folders that is installed by the developer
• never, ever allow the developer to make an update to the codes without informing you, obtain any update : test and backup them!
• if the Sharepoint Wfe's fail, then you should restore from the sharepoint backups and install the custom applications regarding to the documents and files you took backup