As I already stated with a post about my initial grips with WP, I echo the OP's dilemma. I too find it unacceptable to require either an internet connection or to have to install software on a PC. One of the biggest features that I used frequently at work and at my parents' place with extremely slow internet on Windows Mobile, Blackberry, and Android was the mass storage feature. Having a smartphone is about eliminating gadgets: i.e. camera, music player, keys, computer, cellular modem, day planners, newspapers, books, USB thumbdrives, etc.
There are multiple scenarios where mass storage is useful:
1. Computers without an internet connection - How are you supposed to transfer pictures or whatever to this computer? The only way would be to carry a thumb drive around with you.
2. Extremely slow internet, or pay per x amount of data a month - If it was only a 1 MB install file or something, then maybe it'd be doable, but the Zune install is around 125 MB and over dial-up you can just forget about it.
3. Computers where I do not have permissions - I've had to do work on my company's equipment in different countries. Our equipment that we sell is Windows-based and changes to our software was needed. Since the computer is already on the customer's network it had all the security policies in place to prevent new installs, however, I saved the updated files from my email on my BB to it's storage card, then just hooked up to the PC and enabled mass storage mode. Extremely easy and something I couldn't have done with just a WP device as I have now.
4. Similar to above, but company PCs where IT monitors all installs and have a policy against non-work or IT approved software installs. If I want to transfer files like my music so I can listen to it via WMP on my PC I can't as I can not install anything and Skydrive is blocked...as well as personal email websites....and FTP.
While many of you may not have needed this feature I can honestly say I can use this feature at least once a week. I hate having to carry more than I need to and I think a flash drive should be obsolete by now....but that isn't the case if I don't bring my work's Blackberry with me.
Edit: BT file transfer will allieviate some of the scenarios, but not all (my parents and customers do not have BT).
I understand why MS has disabled this and I am not asking for them to open up the entire storage system to the connecting PC's view, just allow me to create a partition on the SD Card that can be a shared data repository, I would be fine with an intermediate storage medium.
PS: If you want this feature as much as I do, please vote here:
http://windowsphone.uservoice.com/f...stions/suggestions/1549645-enable-usb-storage
Obviously myself a few thousand other people feel the same way on this.