My suggestion (and it goes hand-in-hand with catering to different groups of users): decide who and what you want to be.
In MY mind, Twitter’s a text-based medium. Seeing photos, videos, and web previews embedded in my timeline is irritating as all hell. You’re not Facebook, and you’re not Instagram.
Twitter is also a real-time, chronological platform. It’s not Facebook, and it doesn’t have clever little algorithms helping it decide what to show you when.
99% of my time on Twitter happens on my computer, using TweetDeck. I have a constantly rolling chronological stream of tweets, eight hours a day, five days a week. Embedded images and videos are disabled in my columns, because they clutter my stream and irritate me. If I want to see the photo or video, I click the tweet to view its details (I just can’t figure out how to get the video to NOT play sound by default when I do that).
In that respect, kudos for recognising and catering to my particular way of using Twitter. Now, make it so that when I find myself unable to use TweetDeck (like when I DO have to go in from my phone, or I happen to visit the Twitter website), I don’t feel like I’m using a completely different app.
We don’t want to send longer tweets. 140 characters is fine. It’s part of what makes Twitter, Twitter, and it’s in line with the whole “SMS replacement” idea that made it so great.
We (at least, *I*) don’t WANT non-techsavvy, marketing type people on Twitter, with their embedded images and videos, the links to which don’t take up characters. I still want to option to do an old-style “RT @abc blah blah”, or at least have quoted tweets not break the conversation thread. Hell, I’d still like the option of typing “d @abc blah blah blah” to send a direct message!
As Twitter’s evolved, it’s lost its charm, and it’s forgotten what it set out to be.