Thanks Leopold, I've paused and back-tracked a bit, done more researches and it looks like the whole starting point was the Wizard screen "wrong' choice of SQL Server Express although precisely Express is what I've got..  The subsequent struggling was due to this. Cathal also pointed me in that direction.

I will recommend to the DNN core resources to change ASAP the current wizard installation screen "Configure Database Connection" Select Database radio-button field, which as this time states "if you are using SQL Server 2005/2008 Express then you should use the File option".

According to general knowledge and wisdom seen in 3 DNN book writers and bloggers this is just NOT the case, i.e. if you expect to see your DotNetNuke database from within SSMS, then this is the last thing you want to do! But until you know it, you don't, and I've clicked like probably many the 'Express' radio-button, having the 'Express' SQL Server 2008 R2 installed, and comforted by this wizard statement. It should be explicit in the wizard screen, that it's instead NOT the right choice!

We're in 2011, and I see in Mitchel's 2008 blog http://www.mitchelsellers.com/blogs/a...
 that it's been mentioned already as "a very common stumbling block as individuals will know that the database exists, however, SSMS will not show the database at all, until it has ben successfully attached." ...

And people continue to stumble.. and most likely some let the WCMS comparing communities know of their experience.. I think it needs attention quick. Installers like us with an IT background but newer to SQL Server and .NET, go 'Express' for local sand-box installations but not realizing they really click on this 'dynamically attached" database pitfall and won't see a DotNetNuke database from within what their 'duly' installed SSMS.