Did you try Goodreader for managing files and sending attachments while you were using your iPad? It's a bit kludgy but it seems like it it should solve most of your problems of downloading files and then sending multiple attachments.
Yes and thankfully the iPad has that app, it's very nice. However email on Honeycomb is just like a laptop/desktop client. Start the email, click on the paperclip (attach) browse your folders, select file, and add as many files, pics etc.. Hit send. Done.
There are workarounds, I've been using it heavily for the past 9 months. I'm sure if you look through my posting history I probably at one point was bashing Android after the issues with the Evo I tested out for 30 days. However while waiting for the iPad 2 to show up, I decide to try out the Xoom and keep an open mind. After 2+ weeks the email, web browsing, multi-tasking and file system won me over. It simply eliminates many, many steps I have had to do on the iOS to get the same task done.
As I stated before, I want tools that get me from point A to point B as quickly as possible. Honeycomb opened my eye's to some very nice features that iOS, nor apps bring to the iPad. Dealing with attachments on Xoom just makes sense, not having to figure out what app works, which one to copy and forward, exit out of this app, go back into mail, paste... etc... It makes iOS look very dated and lacking.
If iOS 5 brings those types of improvements I"m all about the iPad 2, but currently it's been handed over to the wife to do what it does best. Entertain.