I am happy to report that Dan Wolfgang's brilliant Better File Uploader does work with MT5.
You can only access BFU from the edit/create entry menu by clicking on the "upload image" icon and then selecting BFU as an uploader, but that's a small price to pay.
In its as-shipped form, the cancel button on the BFU screens don't function in MT5. That needs just a small change to the template, .tmpl, files of BFU.
You have to add this to every one of the tmpl files in the lines relating to the cancel button:
class="cancel close action mt-close-dialog"
and turn the "button-type" to "reset" (don't know if that makes a difference; shouldn't)
Therefore,
<button onclick="closeDialog();return false" type="submit"
accesskey="x" title="<__trans phrase="Cancel (x)">">
<__trans phrase="Cancel"></button>
becomes
<button onclick="closeDialog();return false"
class="cancel close action mt-close-dialog"
type="reset" accesskey="x" title="<__trans phrase="Cancel (x)">">
<__trans phrase="Cancel"></button>
After that, it works beautifully and beats the pants off the built-in image uploader which lets you specify a folder to upload your images, but sends the thumbnails it creates off to some other folder which is its "cache" directory.
Reported on Movable Type 5
Congratulations for spotting that Gautam!
I've found quite an ugly bug with Dan's plugin which I'm waiting for him to fix for a few weeks.
Apart from that bug Dan's plugin really rocks!
Haven't worked with this plugin yet but if the problem is that there is no 'Create' or 'Manage' menu in MT5, maybe this solution can help:
http://www.movabletips.com/2010/02/making-some-movable-type-4-plugins-work-on-movable-type-5.html