Thanks to a reader comment, I discovered that bada supports Java ME, which means you can use alternate browsers including Opera Mini, Bolt and the UC Browser. Java support is not mentioned in any of the bada promotional materials I've seen and most reviewers seem to have missed it's existence as well. It's not exactly a secret though. There's a brief mention of Java in the "Games and Applications" section on page 71 of the Wave User Guide (PDF). But who reads the manual? Not me, obviously.
Unlike the buggy and unstable Java VM's on many of Samsung's feature phones, the Wave's appears to be very well done. Performance and stability seem excellent, apps can run in the background, virtual keyboard support works and unsigned apps install and run with a minimum of unnecessary security warnings and prompts.
You can install Java apps by clicking a JAD or JAR link in the Dolfin browser. When the app finishes downloading a notification bar pops up at the top of the screen. Tapping the bar gives you the option to "Play" the game or app.
Installed Java apps don't appear in the phone's main menu. To find them on the phone tap the "Games and more" menu icon to open a scrolling list of all the ones you have installed. Tapping an app opens it or brings it to the foreground if it's already running. A menu button (labeled with three dots) at the bottom of the screen gives you options to rename apps, specify which network APN to use, enable or disable an onscreen virtual keyboard and toggle a "fit to screen" scaleing mode that expands games designed for fixed resolutions so that they fill the Wave's 480x800 screen.
Opera Mini 5.1 (image, top left) looks stunning on the Wave's high resolution screen and everything seems to work perfectly. The bada "Fit to screen" option defaults to on which makes text and images slightly blurry. Turning it off got rid of the blurriness but made Opera's menu text tiny. I prefer it with Fit to Width off but it both ways to see which works best for you.
I used the double signed version of Opera Mini 5.1 and saving pages and file uploading and downloading worked without permission nags. You will want to turn off the bada virtual keyboard to get rid of the unneeded and space wasting cursor key overlay at the bottom of the screen. Don't worry, even with it off a virtual QWERTY keyboard will still pop up when you click on a text box. You can choose between the Samsung virtual keyboard or Opera's with the "Opera Keyboard" setting in the browser's "Advanced menu.
Bolt 2.11 (image, top right) also worked pretty well and looked good. I found I got best results by turning off bada's fit to screen option and choosing Bolt's largest font. I had to disable Bolt's inline-editing in order to get the virtual QWERTY to appear when I tapped a text box. Bolt makes no concessions to touch screen devices and it shows. Clicking menu items is somewhat tricky and scrolling seems "sticky"
The UC Browser 7.2 (image, above left) is also not particularly touch friendly either, with small hard to hit menu items. Unlike with Bolt, scrolling was fluid and fast. Font sizes are an issue with UC regardless of whether fit to screen is on or off. The problem is that the menu fonts are much smaller than the default font used for web pages. The best combination for me seemed to be turning bada's fit to screen option on and using UC's medium font. That gave me reasonably sized menu text, but text on web pages was larger than I would like.
I tried several games and all installed and ran, but not all were playable. Some like Tibia ME couldn't connect, others including Rhynn wouldn't accept the QWERTY keyboard's input so I couldn't log in. The fit to screen option worked with some games but not others. The virtual keyboard's soft keys and arrow keys(image, above right) generally worked well with games that don't support touch.
I think I'll be using the Wave a lot more now that I've discovered that it supports Java apps. Pickings are still a little thin in the Samsung App store. The over 50,000 Java apps in circulation should help to fill the gap.