[css3-marquee] Differences between WAP-CSS and CSS3-Marquee

Ok I've got a 
question about the CSS3 Marquee module.
 
If I have a block 
that doesn't overflow I 
cannot marquee this text back and forth because there is no overflow. Is that 
correct? It seems that this doesn't give the same functionality that WAP-CSS 
provided via the -wap-marquee display style. 
 
eg:
<div 
style="overflow: auto; overflow-style: marquee-block; marquee-style: alternate; 
marquee-direction: reverse; marquee-play-count: 50; background: 
blue">
This is a long 
<br>piece of text to test <br>This is a long piece of text to test 
</div>
 
In WAP-CSS if you 
applied the marquee display it would marquee back and forth.
 
eg.
<div 
style="display: -wap-marquee; -wap-marquee-style: scroll; -wap-marquee-loop: 
50">
 
This is a long 
<br>piece of text to test <br>This is a long piece of text to test 
</div>
 
dave.