I hear people ranting about multi tasking... you have background agents which do that..the application needs to be developed using that in mind. What's the point of having a program run in background when you cannot see it or use it?
I wrote a program which tracked location of the user at a certain interval and it works in background just fine even when the phone is in sleep mode. Is that not multi task?
some comments about the posted "limitations"
3. No mass storage mode.
Not needed it till now
4. No micro-SD card support.
Focus had it but who needs 32GB storage, 16GB is just fine and with 25GB of Skydrive.
7. Need Zune to transfer files. Zune will only transfer photos, videos & music. All other files need to email/upload to yourself.
I have not come across a situation where in i needed a non photo/music/video file to be transferred..
8. Your contact details are automatically uploaded to cloud service whether you like it or not.
how is this a bad thing.. don't have windows live ID if you don't want.. and be a ForeEverAloneGuy 
9. Limited to 800x480 resolution.
Works just fine!!
10. Voice search is hardwired to Bing.
Isn't android tied to google?
11. Cannot use any MP3 file as ringtone except those with strict constraints.
you can use a mp3 file which is 30s less duration.. why would you want to have a minute long ringtone (to annoy others?)
14. Cannot sync directly with Outlook without syncing to Cloud -
whatever contacts which are in outlook aren't they linked to exchange or pop3 or some other online account?
15. Totally closed OS, cannot sideload apps outside MS Marketplace.
In other words, cannot pirate!! but there are ways to achieve this as well, bazaar *cough* *cough*
16. System font size cannot be changed.
haven't done this in any phone which i have used till now
17. Images and photos cannot be renamed in the phone.
don't see a point, when you can't browse by filenames!
18. Windows Live ID account cannot change country once set.
This is valid but more of a microsoft account issue rather than windows phone..
i had to lose my old hotmail account with lots of gamerscore when xbox live came to india, because i had chosen UK as region before to play
21. The idle screen is completely blank and cannot display time or notifications. -
the lockscreen does display the time, notifications
22. Only photos allowed as email attachments, documents not allowed.
method is different, open document then e-mail it
23. Bluetooth does not have rSAP protocol which is the most common protocol for car audio streaming & 24. Cannot stream audio from video to Bluetooth devices (No A2DP).
I listen to my music in my car through my phone itself and through bluetooth. not sure where this came from
Infact it has better integration with car audio system than any other OS. you can even reply to text through voice!
26. Cannot use Bluetooth keyboard.
huh!! what next, cannot use USB keyboard?
27. Cannot silence ringtone or alarm by flipping the phone.
pressing lockscreen would do just fine.
28. Very limited customization option.
matter of choice
29. Cannot be upgraded to WP8 (Apollo)
not confirmed yet.. btw, lots of devices can't be upgraded so?