RazorSEdge

Sent you a PM concerning this.  I gave some detailed feedback on the DevFuse customer forums for this as well. 

This application has been updated with a few dozen minor and critical bug fixes, including a few new minor features. See full list of bug fixes here.
Set max width video independent of default setting. Profile tab support added for members videos. Only upgrade if using IP.Board 4.1.x or later.

Confused by your whole statement... IPS offers the major components of their suite: Forums, Blogs, Gallery, etc... They do not offer themes, modifications, etc... that would be 3rd parties (like myself). 
You get to take with you all your data in an upgrade (this is typical with versions of any software) but things made by 3rd parties such as those themes and modifications are on the old platform and not transferable for a good reason. When you buy a new car, you don't say "How come I can't take my old steering wheel, I really liked that steering wheel!" It doesn't fit on the new car because there is different linkages, sizes, technology, etc... etc... The same thing here, you can't take your old theme over because there are different definitions, sizes, the new one has more features that aren't compatible, etc... The world of web has changed a lot since 3.4!
EVERYONE is in the same boat. I actually turned out 100x more happy re-doing my skin because it was a chance to rethink things since the last time I did it, put in my own upgrades and modernizations, etc... No doubt is this a small project for any admin upgrading but you can't improve while staying the same
I would implore you to read the blogs IPS posted about IPS4 and everything it has to offer and why it is this way. I only am writing a small bit because I believe it is every admin's duty before they complain and do the upgrade, to read through what IPS has to say and why exactly they did things the way they did.
IPS has stated that 3.4 will be "supported" with security fix and support for somewhere around 2 years, maybe longer (don't quote me though just what I've heard by reading  ). Again it is YOUR duty to inform yourself and figure out if IPS4 is right for your community and if/when that upgrade should take place. I am sure there will be people who say on 3.4 indefinitely. There are 3rd party modifications that I'm waiting on fellow 3rd party developers to finish that my forum depends on so I don't foresee my forum upgrading till later this year (of course there are a lot of variables in that estimation lol)