Sometimes I wonder to see the superb images in the review articles. I am not sure weather these images are drawn by professionals or just using skills in corel draw? I really would admire your comments.
Yes, we're using CorelDraw for our publications as well. As they're user friendly, and files can be saved with very high resolution. The figures are acceptable in most publishers (e.g. Scholar One).
We have a number of sophisticated graphical software, for example Photoshop, CorelDraw, Illustrator, MS Visio, etc. Each graphical software tool has its own advantage and can be used for different purposes. For example, for architecture diagram, ER diagram, data flow diagram, etc, Visio is quite perfect. For data plotting, we have a number of tools like OriginLab. These software tools also have flexibility to control quality/size/formats of the produced images.
Other than that we also used GraphPad Prism for statistical figures. We also used VARNA for secondary structure (DNA sequences) illustrations. I agreed with you that each of them serves differently. PS as well, they're more to artistic design so preferred to use them for poster and also figures for presentation purposes. :)
I would suggest the same software already mentioned (Origin, Prism), but also OpenSource tools like R mainly for statistical analysis. R has very powerful plotting packages especially for large multivariate datasets, but is not so easy to use.
For nice images of protein structures then Pymol, Qutemol and Chimera are relatively easy to use and provide very nice figures and movies if required. They are commonly used now for the figures you see in NSMB, structure etc....
I recommend drawing images as vector graphics or exporting images to formats such as EPS (short for Encapsulated PostScript), which is a vector format i.e. scalable, resolution-independent, composed of individual shapes. These features allow vector images to resize easily without loss of quality.
EPS files can be created and edited in illustration programs such as Inkscape (free and open-source), Adobe Illustrator or CorelDRAW.